WG K7000 series (now Wei-Ya 826HR) - replaced width adjustment cap, issues...

[Numbski]

Okay, so I've been tweaking the width adjustment cap, trying to get the picture just right.  I'm noticing an odd side-effect, rather two:

1.  The tube now makes a "sizzling" noise.  I kind of presumed it was moisture that had gotten into the tube being burned off, but it's still unsettling. :\

2.  The picture is wider in the middle, and gets squished off to the sides.  I'm not sure exactly how else to describe it.  It's like the image in the middle is getting stretched wider than normal, and the picture at the sides is squished smaller than normal.

Any ideas?

[Numbski]

The sizzling/popping is getting really disconcerting.  I just noticed with the lights off that the picture is flicking pretty good too. :\

[gokun]

is there any kind of ozone/electrical smell accompanying the noise?
also, can you provide some pics of the picture distortion?
baring in mind I don't know NEARLY what the regs here do, have you checked your tube to see if there are any cracks/breaks in it? or can you see any sparks/electrical 'spiders' etc back there?
could maybe be the flyback going out also...see any cracks in the flyback perhaps?
but again, I am no expert, so hopefully the regs will chime in with some better info for ya in the near future, but in the meantime you have a couple things to check
[EDIT]
This probably goes without saying, but just in case...do NOT touch the thick red wire going to the tube while you're back there...or really anything else for that matter unless you're familiar with electronics. Sorry if you already know that, but better safe than sorry...

[Ken Layton]

With the room lights out (at night) take the back door of the game off and power up the machine. Do you see any arcing anywhere?

Could be the flyback arcing due to cracks in it's case.

Is the high voltage wire (red wire with the suction cup on the end) securely fastened in the anode hole in the picture tube? The clips in the suction cup should snap firmly into the hole in the tube.

Are you using the correct style of capacitor (and voltage rating) for the width capacitor? The wrong style or the wrong value will break down and arc in minutes after installing it.

And last but not least, the yoke might be going bad.

[moose]

I noticed a lot of static crackling on my wg k7000 series monitor after doing a width cap replacement, too. I'm assuming for the time being that it's something along the lines of warming up the tube or something like that.
The picture is fine on mine though, and there are no real concerns other than the little crackles, and the crackles seemed to decrease in frequency (though not stop) after a few minutes of on-time.
I replaced my width cap with a larger capacitance and higher voltage cap, non-polarized.

[Numbski]

is there any kind of ozone/electrical smell accompanying the noise?

Now that you mention it, yes.

also, can you provide some pics of the picture distortion?

I can try.  It'll be tonight though.

baring in mind I don't know NEARLY what the regs here do, have you checked your tube to see if there are any cracks/breaks in it? or can you see any sparks/electrical 'spiders' etc back there?

could maybe be the flyback going out also...see any cracks in the flyback perhaps?

I hadn't noticed any, but I'll try more closely inspecting it.

This probably goes without saying, but just in case...do NOT touch the thick red wire going to the tube while you're back there...or really anything else for that matter unless you're familiar with electronics. Sorry if you already know that, but better safe than sorry...

Yeah well - the thing fooled me last night.  This is the first time I've truly had to discharge the tube.  Last time it had been shut off for months - apparently long enough for the charge to dissipate.  It's a trial and error thing getting the width right, and I'd though I'd probably discharged by touching the clip.  NOPE.  Went to put it back on and the thing bit me.  Not as bad as I'd thought, but my thumb was swollen up pretty good for most of hte evening.

[Numbski]

With the room lights out (at night) take the back door of the game off and power up the machine. Do you see any arcing anywhere?

When the picture flickers, it appears to arc a little inside the tube at the very back.  I feel like I'm confused about what the flyback is now.  I thought it was the very back part of the tube.  It isn't the white plastic box on the neckboard, is it?  There's a little bit of exposed wire on the outside of that (oops! that was a mistake from when I couldn't figure out how to get the neckboard off - I do-soldered that wire, and re-did it.  Apparenlty it wasn't a perfect job).

Could be the flyback arcing due to cracks in it's case.

Yeah....see above.

Is the high voltage wire (red wire with the suction cup on the end) securely fastened in the anode hole in the picture tube? The clips in the suction cup should snap firmly into the hole in the tube.

So far as I can tell, yes.  Granted, the thing DID bite me pretty good that last time  I guess it's possible that it's not on as tightly as it should be.  I kinda wanted to get my courage back up before futzing with it again.

Are you using the correct style of capacitor (and voltage rating) for the width capacitor? The wrong style or the wrong value will break down and arc in minutes after installing it.

Well, I got the kit from Bob Roberts:

http://arcadecontrols.com/BBBB/width.html

What I found was that a .1uf cap was way too wide, but a .22uf was too narrow (although I think I was failing to give the ferrite adjustment slug enough credit), so I chained a .22uf and .33uf in series, thinking that would give me .11uf-ish.  I'm tempted to go back to the .22uf and try to be a bit more aggressive with the ferrite slug, but the page says not to.

I'm wondering why you couldn't just use one of these instead:

http://www.oselectronics.com/ose_p96.htm

Put it in and adjust accordingly...I'm guessing there's a reason why you don't do that, but I don't know what it is.

And last but not least, the yoke might be going bad.

I don't suppose there's any way to test for that?

[Numbski]

Well crap.  I was reading, and apparently the "correct" value for this is a .39uf.  Meh...

[gokun]

As I understand it, the flyback is that black plastic thingy with the screen and focus knobs on it that the red anode wire connects to on the chassis board...
but if the arc is coming from the back of the tube area I would think the flyback isn't the issue...again, the regs know more than me and can give you a firmer answer on that one...
the arcing thing worries me somewhat though....can you closely examine the area where you saw it, while the monitor is off, for cracks or breaks?
And yeah, I would definately replace that cap with the correct one...
as for the yoke, I do not know how to test them but I believe the yoke is the area around the back of the tube where you saw the arcing, so that might not be good...
anyhoo, the regs will be able to give you better info when they come back around...just trying to help out a little in the meantime.

[grantspain]

did you mess with one of the high voltage polypropylene caps??
if so what was the original value(i.e 473j 1500v) and what value did you put in?

[Numbski]

I only replaced what was in the Bob Roberts Cap Kit, and those were 1:1 values.  C38 is the only one I took liberties with.

Also, the two things seem to be related.  The sizzling, popping and cracking have ceased after I went back to the .39uf cap, and all distortion is gone, but now the picture is far too narrow.  I put in a .22uf cap, and here's what the picture looks like.  Sorry about the quality, it's off of my camera phone:



Pay special attention to the letter in Blanka's name.  The one at the far right on player 1 vs the one on the far right of player 2.  That doesn't happen with the .39uf cap. :\

[grantspain]

pull up a grid pattern in test and look at the geometry

[Numbski]

Give me a sec.  I was testing to make sure I wasn't going insane and put a .1uf in at C38:



So I'm right, I need something greater than .1uf, but less than .22uf.  Fun.

[grantspain]

whats the exact chassis here,it looks like a 19" but is it a 7200 or 7000

[Numbski]

Here you go!

[Numbski]

whats the exact chassis here,it looks like a 19" but is it a 7200 or 7000

I never did find out.  It's definitely an older revision - it doesn't have the external pot board for adjusting height, brightness, contrast, etc - that's still on the main board.  Also, this isn't a 19".  It's a 25" (diagonal). 

[grantspain]

yes it the old 7000 chassis,this cap you changed a c38-what is actually written on it,it should say 394j 200v
also important to note that cap is right in line with the horizontal linearity coil

[Numbski]

"Linearity Coil".  You mean the ferrite slug I keep adjusting?

Anyhoo - any cluse as to why this is happening?  394J means what exactly?  I know 39, 4 zeroes - so 390000, and Mr. Roberts says to move the decimal point 6 places to give us uf, so .39uf.  Originally, before I did the normal cap kit, the picture was too wide at .39uf.  Now after the cap kit, it's too narrow at .39uf, and putting a smaller value  at C38 does make the picture wider, but it also distorts the image.

What does the J, or K, or JK on some of these caps mean?

[Numbski]

yes it the old 7000 chassis,this cap you changed a c38-what is actually written on it,it should say 394j 200v
also important to note that cap is right in line with the horizontal linearity coil

Somehow I missed that this was a question, not a statement.

394J
200  t

I currently have a .22uf in it, but I still have the .39uf.

F224K @
630MPP1

[grantspain]

i would put the original value caps back in and then look at the grid pattern,if you then have too much width but correct geometry perhaps you are looking at a different problem

[Numbski]

The issue was actually not enough width, but correct geometry. (After I got the board repaired, that is - prior to the cap kit, it was too wide, but correct geometry at that value)

I'm suddenly glad I outboarded C38 to perfboard.  It's saved me a TON of time doing these tests.  Bob Roberts seems to always have great suggestions.

[Numbski]

Well, crap.  The geometric distortion is identical to the image above, only on a smaller scale, so it was less noticeable.  That grid makes it much more obvious.

CRAP.  Now what???

Oh, in researching this, I've learned a few things.  A couple of good resource pages:

http://www.repairfaq.org/sam/flytest.htm
http://www.overclockers.com.au/wiki/TV_/_Monitor_/_Fault_Diagnosis

And since the Bob Roberts page now makes sense in retrospect, the way to calculate the capacitance of two caps in series (end to end daisy-chained) is this:

(cap 1) x (cap 2) / (cap 1) + (cap 2)

Literally the product of the two divided by the sum.  Makes sense when you're in a mathematical state of mind, but for some reason I kept reading it as the sum divided by the quantity, or:

(cap 1) + (cap 2) / 2

Don't make that mistake.

[grantspain]

if your width is now functioning then i would look to the linearity coil,maybe its broken-some lin coils had an ferrite core that could be adjusted

[Numbski]

Nope, width is even LESS functional now.  I need to tweak the value of C38 to get the width right (unless there's another way to do it?) as right now the picture only takes up 2/3 of the tube.

Yeah, the ferrite slug next to it is what I was trying to adjust.  You mean that coil around it would cause the geometry distortion I'm seeing if it's busted?  I don't mind ordering a new one (and in fact Bob Roberts has a kit with that, the Flyback, and a couple of other parts I might as well get while I'm at it just to be sure.

I'm just wanting to understand what might be causing it before I throw more parts at it.  If the concensus is that the proper value cap should not be drawing a picture that small, then I can get these other parts and clean things up.  I can also continue tinkering with the width using C38 - but if I'm wasting my time there, I'll quit.  I think I'd like to order a new .39uf cap though - the original is looking pretty crusty, and the kit I got from Bob Roberts did not include one.

[grantspain]

wierd,i think you could have a broken width pot and a problem with the lin coil
no one has changed the flyback on this have they?

some of those caps are important to be their original value unless you want to be sterilised

[Numbski]

Just so we're on the same page here (literally):

http://arcadecontrols.com/BBBB/width.html

Again, all caps were replaced with the same value, except C38 - per that page.  I've put the original cap back in.  Original symptoms were picture too wide, colors bleeding a bit.  I figured I'd do a full cap kit, and adjust the width.  After the cap kit, the tube wouldn't fire up.  Finally took it in for repair and was told that "a transistor was shorted", brought it home, fires up just fine, but now it's far too narrow.  That leaves me to adjust C38, and in the process of doing so I noticed that it wasn't "just fine", but the geometry is what you see above.

If the coil can/does cause this sort of thing, no problem - I'll order a new coil.  I'm just hesitant to throw parts at a problem if that part isn't known to cause this sort of issue.

[Numbski]

.149uf seems to be about right on the width, but the picture on the right side rolls over onto itself. :\

That, and of course the omnipresent geometry problem remains.

[Numbski]

Looks like this same issue came up for the user "dabone".

http://forum.arcadecontrols.com/index.php?topic=18527.0

Apparently C37 impacts this too - and the guy that fixed my chasis could very well have changed it - it certainly looks new.  The manual says C37 should be ".15".  Am I safe to presume that's .15uf, 200V?  If so, where can I get one?  There's not one of that value in my cap kit. :\

[gokun]

I get most of my caps from either http://www.digikey.com/ or http://www.jameco.com/
You could see if either of them has it(got all the caps for my wg from digikey last time).

[Numbski]

I'm starting to wonder about the HOT (horizontal output transistor):

http://www.neo-geo.com/forums/showpost.php?s=d6db37d151cffece854bbf007ab5795b&p=2580690&postcount=8

The narrowness problem fits, but I can't tell from the picture - he has a later revision K7000 series, so the board looks nothing like mine.  I don't know where I would find the HOT on my board.  Since the guy that did the repair clearly stated that "a transistor was shorted", it makes me wonder....

Anyone know where it should be on my board?

[Numbski]

After going through many images, I'm about 99% certain that this is a Well Gardner 25k7191, FWIW.  At very least the board layout is nearly identical.

http://forum.arcadecontrols.com/index.php?topic=30237.msg255973#msg255973

[grantspain]

I'm starting to wonder about the HOT (horizontal output transistor):

http://www.neo-geo.com/forums/showpost.php?s=d6db37d151cffece854bbf007ab5795b&p=2580690&postcount=8

The narrowness problem fits, but I can't tell from the picture - he has a later revision K7000 series, so the board looks nothing like mine.  I don't know where I would find the HOT on my board.  Since the guy that did the repair clearly stated that "a transistor was shorted", it makes me wonder....

Anyone know where it should be on my board?

thats not a HOT,its the width transistor-i am not sure how your chassis does the width,normally these are direct to the bridge coil in the circuit

[Numbski]

Horizontal Output Transistor (ie width) is not the same as the width transistor?  What's the difference?    

[grantspain]

http://www.repairfaq.org/sam/reppic/horiz-tv.pdf

explained better than i ever could

[Numbski]

Okay - well, I located C37, removed it - and it's the .15uf variety alright - but I found something soldering across it in parallel on the solder side:



It's labelled:

IN4936
GI 823

Best I can tell, it's a capacitor too.  I didn't put it there though.  Problem is, I tried running without it, and something arced on the neckboard between the 4-pin molex and the connection to the tube.     I immediately shut it down after that.  I can't tell the value of that cap, and I tried outboarding C37 too, since it's too much of a pain to keep putting back in there, but yikes...

EDIT:

CRAP!  That was D15!  Someone removed it and then soldered it back onto the solder side of the board!!!   Ick.

[grantspain]

no thats a diode mate,you will end up killing yourself the way things are going-probably there to prevent reverse current

[Numbski]

So I noticed, although I tried putting it back and the neckboard arced in teh same spot again.

Okay, I think I've lost my nerve for one night.  I'm going to sit tight until someone can give me a hint on how to proceed without winding up dead.


EDIT:
So I lied - I got the diode back in.  It would figure that on a 50/50 shot, I'd put the diode back in backwards.  Ugh...I still don't know what to do about the picture other than start buying a bunch of parts for the width circuit and hope that I find the bad one.

[Numbski]

I'm about ready to give up and pitch this thing.  Makes me mad - this was working fine before the cap kit, it was just too wide.  Now it's like everything has gone nuts.

 

I'm literally out of ideas.  I hate the idea of just randomly buying a bunch of parts and replacing them all - I tend to like to know what causes a symptom, and fix JUST THAT.  Doesn't make sense to throw parts at something and not know why you're doing it.  Right now I've had the following named off:

Flyback
Yoke
HOT
Width Pot
Width Coil

So....I guess I could buy all of those things and pray, but is there one that's more likely the culprit than another?  Is there *any* way to logically test through this to narrow it down?

[Ken Layton]

Parts you see soldered on the foil side of the board were put there on purpose by Wells-Gardner as part of their undocumented production improvements. Never remove them!

You say it was fine before you started working on it so it's obviously something you did and you're making things worse.

Perhaps you should cut your losses and just buy this brand new replacement chassis:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150294277959&refid=store

It has a jumper to select the width range (narrower or wider) plus the most commonly need adjustment controls on a remote board.

[Numbski]

I'm certainly not opposed to it.  Just confused as all get out. :\  Cap kit, now this.  Feh.

[Numbski]

Okay, I'm cursed.  That's all there is to it.

I ordered the chasis in the link above.  What I got in the mail was a Wei-Ya 826HR.

I carefully go about wiring it up - given that it came with no instructions, manual, nothing.

Turn the thing on, it immediately blows the 2A fuse next to the AC power in (really a 3A).  I go back, remove the chasis - re-mount it so that it's not touching the frame that holds the tube, put a 2A fuse in, turn it on, blows the 2A fuse - AGAIN, immediately.

I am *so* running out of ideas.  The only thing that has me even the slightest bit concerned was that one wire harness coming off of the tube was colored slightly different from the original, but the connector was the same, right down to the keying.  From keyed end over, the new one was colored  red, blue, yellow, green.  The original one (which is still the one in use) is colored red, blue, brown, yellow.

I did some searching, and I'm starting to wonder - the frame holding the tube - it appears to be connected to the ground circuit running throughout the cabinet - so I am not entirely sure what to think.  The ground wire coming off the neck board is a black wire that turns into a long length of exposed braiding.  I've connected that back up where the old neck board was grounded.  The new chasis had a new R, G, B, sync harness, so I wired that in where the old one was - but given the way that 3A fuse flashed immediately, I tend to think that it's somewhere in the AC/DC transformer that things are going awry.  The thing has it's own "lamp cable", which I've plugged in for now, but would eventually like to remove and wire back into the master power switch for the cabinet.

Suggestions?

[Ken Layton]

Here's the instructions:

http://home.earthlink.net/~arcadeparts/id11.html

Hopefully you did NOT plug the power cord into a wall outlet. This chassis must be powered from an isolation transformer.

[Numbski]

I did.

Based on those instructions, that's the only error I made.  Hopefully the fuse spared me.  I'll replace the fuse, run it through the transformer and pray.

[Numbski]

Okay - replaced the 2A fuse, wired the monitor in via the isolation transformer, fire it up - and the fuse doesn't blow, but I get a solid white screen.  Try feeding it video, still get a white screen.  My signal lines are run in too.  I'm going to work on tracing my cabling to make sure I didn't foul anything else up - but at least the white fills the screen, rather than a nice white box in the middle.

[Numbski]

Update - we have picture.  It's over-saturated, and it's UPSIDE DOWN, but we have a picture.

Make that upside down and backwards.  It's like I have the yoke plugged in backwards, but it matches the pictures...?

Since I'd done so many stupid things - is there any harm in me plugging the yoke plug in the other way?  From the flyback, I have it plugged in red, blue, brown yellow, just as in the pictures.

[Numbski]

ok ok ok - I get it now.  I think.  Someone please confirm before I kill this thing or myself.

The thing is yoke-flipped.  No clue how it happened, but I see in one of the pictures he's cut his plug in half.  So even though it shows red, blue, brown, yellow - I really need it to be blue, red, yellow, brown.  Sound right?

[Numbski]

Well - after months of frustration - I'm back to where I started, only slightly worse off.

Picture is back up - almost completely normal.  The picture is back to being too wide (can't seem to find my plastic tool to turn the horizontal adjustment coil), and now the picture is waving.  I thought maybe the speakers I'd installed were doing it, so I removed those, degaussed, and still get the waving.  On top of that, I'm seeing "refresh lines", coming top to bottom.

So I guess this is progress - so long as I like SFII waving like a flag.

[Numbski]

Found my adjustment tool.  Then I promptly found that the ferrite slug in this thing is flat, and can't be turned.

Well.  It's time for bed I think...I've got the pot on the control board turned all the way down, and in the "dot cloth" screen, half of the squares on either side is overscanned off screen.  Flag waving and refresh lines are still present.

[Ken Layton]

Screen control is probably a tad bit too high and should be turned down a little. I think on this chassis there should be a "N" (Narrower) and "W" (Wider) jumper wire to move that sets the width range.

I also think this chassis has two yoke connectors to choose from: one gives a mirror image and the other gives a normal image.

Never plug or unplug any connectors with the power on. Same with moving the N or W jumper wire.

I'm surprised you didn't get the 825 chassis which is made for 25" tubes. The 826 is made for 26" & 27" tubes I think.

[grantspain]

for the flyback lines adjust the screen volts,its kinda like a pre brightness adjustment-its on the flyback transformer below the focus adjustment

[Numbski]

For once my suspicion was kinda right - (BTW, I've done computer hardware repair, programming, and networking engineering for well over 12 years, my father however was a TV repair person in high school!), and I had my wife watch the screen, I turned the screen pot down until the picture disappeared, and then slowly turn it back until she saw an image again, then turned the brightness back up.  "The flag was still there".  (sorry)


I'll go looking for that jumper.  With everything being in chinese, but with english in fine print, makes for difficult hunting.  Go fig that the the two plugs weren't the same - I was just following the pictures.  Oh well, no harm done.  I'll try finding that jumper, and see if I can turn the screen pot down any further.

[Numbski]

Pulled the board, and you're right - there are jumpers for both H and V, N and W.  Both were already set to N.

There was an adjustment pot for b+, which in my searching I seem to recall someone talking about flagging from a bad b+ cap, but I don't know if an improperly adjusted pot would do the same thing.

So it looks like I'm screwed on width anything I go futzing with the width adjustment cap.  Again.  I'll see what I can do about the flagging before I mess with that.

Anyway, the auction even listed this model number:

[Numbski]

I don't suppose there's a manual for this chassis floating around someplace?  The reason I ask is that I'm looking at the RBG harness - and the K7000 (if I recall) , could either take H Sync and V Sync separate or composite.  The marking on the chasses for the harness is halfway covered, but as far as I can tell it reads:

R G B B S

It occurs to me that this means red, green, blue, BLACK, sync (I had to presume this was ground).

So - I guess I'd like to confirm that this doesn't have the ability to take separate H and V sync.

[Numbski]

Here's the state of things as I head out this morning.  WARNING!  Turn off your speakers - YouTube completely hosed the audio on this recording.  It's fine on my local copy. :\



The waving isn't caused by my camera - it really does look that way, with about 1/2 inch of overscan left and right.

[Numbski]

Hey grantspain, you get around:

http://forum.arcadecontrols.com/index.php?topic=85134.0

That board is very, VERY similar to mind - some pots are populated on his board that aren't on mine, but it's starting to look like the Pentranic CH888 is a very similar, if not identical chassis to the Wei-Ya 826HR.

So - you made a comment about him having the sync wires hooked up wrong.  My signal harness (now that I have a schematic to go by!) is R,G,B,E,S (or I guess it could be G, S) - and it looks the same as his.  I don't see a separate hookup for v-sync though...where were you getting that from?

[grantspain]

o.k i reckon there is a quick fix for this,i am gonna get flamed from the other techs here but what the hell
you chassis is for a 26" tube but you have a 25" tube-so the logical step is to send it back and replace it for the correct one
now if you do not want to do that then there is one other option without messing with cap values
turn down the b+ adjustment,when you do this your height will increase but i reckon you can adjust that out easily

[Numbski]

Now I had tried to turn down b+ this morning, but it had no impact on the waving.  Are you saying that if I crank down b+, adjust out the height that it would fix both the waving AND the geometry? (I'm at work, can't test it just now...)

Just for reference (I *really* don't want to go this route...), can you tell from the Pentranic schematic which cap is the horizontal width adjustment cap?

[Ken Layton]

The "ripple" in the picture could be from your video signal cable being near AC power wires. The video signal cable must be dressed away from any 120 volt AC power wires. It's also possible that when you connected this chassis without isolation transformer you may have damaged an electrolytic capacitor in the monitor's power supply section.

[Numbski]

From a glance at the schematic, L301 is the width adjustment coil with (apparently immobile) ferrite slug, and that makes C315 the width adjustment CAP, with a current value of .39uf (394J/250V).  I forget what caps I have back at the house, but I'm thinking if I do .40uf or .42uf as a last resort I should be in good shape.  That of course presumes I get the waving under control and there's absolutely no other way to fix the screen's geometry.

If someone could be so kind as to verify.    Please....I'll send out beers over TCP or something over this.  Amazon wishlists?

[Numbski]

The "ripple" in the picture could be from your video signal cable being near AC power wires. The video signal cable must be dressed away from any 120 volt AC power wires. It's also possible that when you connected this chassis without isolation transformer you may have damaged an electrolytic capacitor in the monitor's power supply section.

Yeah - I was kind of afraid of that.  If that's the case at least it's not TOO big of a deal to find those caps and replace them. :\

[grantspain]

the wave is nothing to do with the geometry problem
you probably screwed the mains filter cap when you connected this direct to mains

the b+ is something i would be a lot happier adjusting down rather than messing with cap values
b+ adjusting up=bad
b+ adjusting down(a little)=no big deal

[Numbski]

Well - turning B+ all the way down along with the width pot all the way down does nothing. :\

So far as the waving, the mains filter cap - if J801 is the mains coming in, that makes T801 a switched transformer (I think?), so C801 is the "filter cap"?  I'm not too good at this, it is labelled 0.22U/250V I'm not sure what the capital U stands for.  Is it just a .22f cap?

[grantspain]

well first time i have ever heard of the b+ making no affect
perhaps you have killed the b+ filter cap

[Ken Layton]

Main filter capacitor would be the largest (physical) electrolytic capacitor on the main board.

[Numbski]

So far as I can tell, this is the schematic for this board.  Some of the positions are labelled ever so slightly different, but the values and positions match up.

[grantspain]

ch888 is a free voltage chassis that runs without the need of an isolation transformer,are your sure that it not a ch666 chassis which 120v isolation only

[Numbski]

Well, I have the chassis out now.  That would explain the labelling differences.  I'll take some hi-res pics here in a few minutes - is there any relatively fast way to tell?

BTW - the filter cap on this board (based on Ken's description) is 680uf 200WV - that would tend to corroborate your idea, since they'd want at minimum a 250WV cap there I'd think, and in fact on closer inspection, the schematic here calls for a 250V.  Lemme go pull the ch666 schematic.  Dang this thing matches so closely though...

[Numbski]

Are you sure you don't have those backwards?

CH-666 (Analogue Chassis – CGA/EGA/VGA) - 28", 29", 38"
CH-888 (Analogue – CGA) - 14", 17", 19", 20"

I think we're both wrong and it's this one:

CH288 - CGA (Analogue - CGA) - 26", 29", 33", 38"

[Numbski]

Okay, so one is the overhead view, the second is what I think is the filter cap.  My side views came out blurry, so I'm going to re-take those.  Compare with this image from the other thread:





I don't have the yoke plug attached, so that seems to be glaringly absent, and the top-left set of pots is not populated, but that's because they've wired it outboard (attached).  The general layout and just about every component matches up.

[grantspain]

sorry i was helping someone with a 666 in another forum and got confuzzled
again the 288 is free voltage
now the 988 is 120v only so check that out

[Ken Layton]

That's not a picture of a Wei-ya chassis. That's a Kortek.

[Numbski]

Ugh - you've got to be kidding me.  They sent me a Kortek chassis in a Wei-Ya box???  Sheesh.

(oh wait, the top image is someone else's chassis, the bottom pictures are mine)

[grantspain]

wei ya and rodotron are basically the same although there are some variations,the basic chassis is the same
i have been looking at your pic and the 988 schem and i believe they are the same

your chassis is without doubt a 120v isolation chassis

also i wonder if the wave problem is down to the degauss,try the monitor with the degauss disconnected otherwise i would go for the large filter cap in the top right hand corner
important to check those diodes as well in the bridge circuit

[Ken Layton]

The large 680 uf cap is the main filter.

I now see your pictures correctly. Earlier when I clicked on them I had a "permission denied" page pop up.

On your chassis is a second red wire jumper near the wide-narrow jumper. What does this other jumper do? What are the markings next to it?

[Numbski]

I'll check in a moment.  I managed to snag a replacement filter cap locally.  The waving remains.   I guess the B+ cap would be next. :\  I believe the other jumper was Vertical Wide/Narrow.  I'll check as soon as I can.  I haven't tried running without the degauss cables hooked up.  I can try that too, but I'm puzzled as to how that would help.

[Numbski]

Okay - the jumper nearest to the width adjustment coil is labelled "V", with two choices "W" and "N", with "N" selected.  The other one is labelled "A", with the same two choices, "N" selected.

[grantspain]

I'll check in a moment.  I managed to snag a replacement filter cap locally.  The waving remains.   I guess the B+ cap would be next. :\  I believe the other jumper was Vertical Wide/Narrow.  I'll check as soon as I can.  I haven't tried running without the degauss cables hooked up.  I can try that too, but I'm puzzled as to how that would help.

coz i am wondering if the degauss circuit is constantly on-which would cause waves

[Numbski]

Running with the degauss cable unplugged makes no difference, the waves remain.

The two yoke plug outlets behave differently - one runs the picture upside down, the other is backwards.   No matter which you choose, you have to yoke flip.

So what really should be the next step here?  I get the feeling I should tackle one problem, then worry about the other.  Since we know it's not the filter cap causing it - I've gone and cleaned up any A/C wiring that could be suspect, and it doesn't appear to make any difference - the signal cables are well clear of any A/C wiring.

I suppose I could order a cap kit for the thing, but we're kind of chasing our tail at that point.

Pentranic doesn't list a 988 model schematic for download.

[grantspain]

i would send the chassis back and swap it for a 25" version,just tell them it did not work on arrival-wei ya and rodotron are crap quality control anyway,i have had 4 rodotron and 2 wei ya chassis and had to repair 3 of these on arrival due to bad soldering
the yoke thing would require you breaking the yoke plug in two

you have so may different issues with this chassis that it seems pointless trying to get it right

[Numbski]

I'm inclined to agree, but *dang* this is frustrating.

[grantspain]

you can't polish a turd mate

[Numbski]

Yeah well - that's 2 chassis' I've gone through with no luck.  There comes a point when you start to think nothing is going to work.

I'll admit that I've screwed things up these last two times, but still - you'd expect maybe I'd catch a break somewhere along the line. :\

[Numbski]

Since we're on the topic of polishing turds (yuck)....

Let's say I got a refund on this chassis.  Given that I have a 25 inch tube, and that it has a pretty nasty scratch on the front of it - is there a chassis that is known to be of solid quality I could get to go with this, or am I pretty much SOL unless I bought a new tube too?  I'm trying to avoid having to pay shipping on a tube.

[grantspain]

tbh i think you have been unlucky with this particular chassis,get the company to swap it
i bet the 826 works with a 25" tube just fine-maybe your chassis had a fault from the start

you gotta give the fella a chance

[Numbski]

Why don't I complicate this while I'm at it?

I just got offered a 27" television that "won't turn on" tonight.  For free.  Hmm...

[grantspain]

if the tv fits in your cab then bingo,you need a multimeter to make some basic checks but you should be able to come up with a chassis that fits

[Numbski]

Well, I'll be picking it up this afternoon.  Here's to hoping.   The only thing I'm concerned about is the frame that holds the tube.  I don't know if I have to mod the one I have, or if there will be something similar in the TV I can scavenge or what.  Lots and lots of questions.

Presuming this works, then I'm going to have a K7000 tube and chassis just sitting here. :\

[Ken Layton]

If the tube and yoke of the tv set meet the correct specifications of the Wei-Ya chassis, you could "build" a monitor by using the tube & yoke from the tv, the Wei-ya chassis, and use the frame from the Wells-Gardner.

[Numbski]

Okay, this is a new 27" RCA tube.  The yoke wires are Yellow and Green (Vertical?) + Brown and Red (Horizontal?)

Based on my measurements, I'm getting 8 Ohms across Vertical, and 1.3 Ohms across Horizontal.  If I'm reading things properly then URL (http://www.genao.com/datatech/monitor.html):

"Measure the vertical ohms, it should be 6 ohms to 12 ohms. Provide the following information :

  Note: if the horizontal ohms is less than 1.5 ohms , take a 5 to 10 watt 1 ohms resistor and add it in series to the circuit to increase the ohms ...."

So I need to trace the Brown and Red wires back to the circuit board and jump the resistor between the red and brown?  Or do I put it inline to red or brown? (ie, cut the red wire, and put the resistor in between the severed sides of the red)

The next statement he makes bothers me:

"All 25 inch or bigger CRT's are 10 pin connector. "

Both my 25 inch and 27 inch tubes are 8-pin connectors.

Finally, on my 25 inch tube, I have 1.8 Ohms horizontal, 11 Ohms vertical. 


In summary:

Old Tube:
25 Inches, 8 pins,  Horizontal 1.8 Ohms, Vertical 11 Ohms

New Tube:
27 Inches, 8 pins, Horizontal  1.3 Ohms, Vertical 8 Ohms

So the only thing I'm missing is a resistor and how I install that resistor, then we should be good for a test drive?

[Numbski]

Here's some shots of the new tube:

[Ken Layton]

Your new tube and the old tube are considered ten pins. I looked up your new tube and it's ten pins.

The pair of yoke wires that shows the lowest resistance is always the horizontal section. The vertical section will always read higher resistance than the horizontal section.

The yoke on the 27" tube will read less resistance than the old yoke because the yoke has to work harder to deflect inside a 27" tube than a 25" tube.

You don't need to mess with installing a resistor on the circuit board. Simply cut the middle of one of the horizontal wires and solder it in series.

[Numbski]

That answered my question.  Thanks!

[Numbski]

Heh - I don't suppose you guys know where I can hunt down a 27" monitor frame?  I might be able to widen my 25" frame, but it's going to be too short not matter what I do.

[Numbski]

Alright, I did install the resistor behind the yoke connector, that way there's no strain on the yoke plug cable.  The horizontal now reads 2.3 Ohms.

[Ken Layton]

Make sure the resistor's leads cannot accidently come into contact with any other electrical parts that it shouldn't.

Here is a way to widen the monitor frame. Cut a piece of wood to fit between the two outside frames.

[Numbski]

It's not the width I'm concerned about - it's the height. :\

I'm way ahead of you on the resistor.  These were taken before I've had the chance to pull out the heat gun on the shrink sleeve.  I basically just cut down a small piece of perfboard, zip strapped it to a plastic strain relief, shrink sleeve over any exposed wiring, and hot glue over any exposed solder on the perfboard.

[Numbski]

Yeah - i just pulled my glass and bezel - the 25" mounting braces are split at ~16.5" on center, and the new one's mounting braces are vertically split ~18.5" on center.  The existing braces are 2 inches too short.  I can replace the wood and make it wide enough, but not tall enough.

[Numbski]

Finally fired this new tube up tonight.

Nice crisp colors - with refresh lines, wavy picture, and horizontally overscanned image.  In other words, same issue.  So....this chassis is going back.  I got permission to exchange it, and that's what I'm going to do.  In the meantime I can work on how I'm going to get this thing into my cabinet.  Turns out it's going to be too deep to close the back as-is, so several modifications would be in order.  I may just set the newly modified tube aside for now until the new chassis shows up, then worry about it then.

[Numbski]

OW!

I discharged that tube, then waited, discharged it again, etc.  15 times.  I finally moved the thing.

Shocked me in the stomach. OUCH.  That's just not fair.

[grantspain]

OW!

I discharged that tube, then waited, discharged it again, etc.  15 times.  I finally moved the thing.

Shocked me in the stomach. OUCH.  That's just not fair.

did not discharge it then

[Numbski]

It sparked the 15 times I did it.  I may wind up buying a HV Probe out of sheer paranoia after that.  DO NOT WANT.

[grantspain]

you must be discharging incorrectly,most the time i don´t bother unless its a really old chassis like a microvitec
you need an insulated long flat screwdriver and a croc lead-connect one croc clip to the dag earth of the tube(the earth braid that goes across the back of the tube) then connect the other croc clip onto the metal shaft of the screwdriver and then insert under the anode cap until it makes contact with the internal u-clip whilst only holding the insulated handle of the driver(if you are a big girl you could always wear some rubber gloves)
obviously don´t do this with the power applied
  that is what you hair will look like if you try it with the power applied

[gokun]

I can take you a pic of my discharge tool if you want

[Numbski]

Nah - I'm breaking out the heavy artillery next time.  I had already bought a super-insulated *BIG* screwdriver, and had copper tied to the ground on my nearest power outlet.  Next time I'm bringing in my jumper cables from the truck, clamping one end to the screwdriver, and the other to my water pipes.  If that doesn't do it, I'm just screwed (if you couldn't figure that out already from the rest of this thread!)

Now - couple of thoughts.

1.  It is impressively difficult to find an empty 27" frame.  I've called several repair shops, one that says they tossed one in the trash on Friday! (doh!) - all of which say they'll call me if they have another one come though (but I'm not holding my breath).  Modding my 25" chassis seems less and less like a plausible option, and the fact remains that other than a scratch in the front of the tube, there's nothing wrong with my 25".  Which brings me to...

2. The original chassis.  I'm looking at it, and it looks like there's a jumper on that board.  I need to drop an e-mail to the guy that "repaired" the board last time.  I have a sinking suspicion that he changed something.  If he did, I need to know what and undo it, if for no other reason but to let it go on Craigslist to the next guy that needs a monitor.  I feel awful trashing something that clearly has the potential to work just fine, and I'm just too inept to get straight.

[Ken Layton]

If you're talking about the original k7000 chassis, there is a black jumper, a capacitor or two, and sometimes a resistor soldered to the foil side of the main board. Parts of Wells-Gardner's undocumented production improvements. Never remove those parts.

[Numbski]

Not arguing, not contradicting - but I have to ask:

Why put a jumper on a board that is never intended to have but one setting?  Isn't that the point - to have more than one setting?

[Ken Layton]

The black jumper wire on the foil side of the k7000 main board corrects a ground problem in the layout of the foil. Wells discovered this after the boards went into production.

[Numbski]

Ah ha.  So it's a jumper between "working" and "not-so-much working".  I suppose that's two settings.

[Numbski]

Just a short update here.  The day after my last post, I shipped my Wei-Ya chassis back to the seller.  They received it last friday, but as of Tuesday I hadn't heard anything.  I wrote them, and they behaved as though they didn't know anything about it (despite giving me the address to ship to, I have delivery confirmation and tracking number that says it got there), and haven't heard anything again since wednesday.  This is starting to look very bad for me.  Again.

[grantspain]

perhaps they are trying to work out why so many component values have changed in the post

[Numbski]

Oh hush.  Everything was stock that I sent back.  No - not acknowledging something that was signed for and arrived there a week ago has me more than a little worried. :\

[Numbski]

Just a quick update again.  They acknowledged having my chassis, but no word on actually shipping me a replacement. :\

[grantspain]

perhaps they are repairing the  chassis you sent

[HaRuMaN]

wow...

an epic journey to replair a monitor... lol

FWIW, I bought an Wei-Ya 826HR for my 25" WG in a dedicated Mortal Kombat, and it worked perfectly out of the box.  Sounds like their quality is a crap-shoot, though.   

[Numbski]

I got this from the seller today:

"I have checked and tested the chassis, we replaced a transistor on the power  supply ( maybe it was the reason)
We have pre-adjusted every potentiometer to  get the right picture on the CRT ( color, Brightness, v-size, focus, etc, etc) . Maybe you need to re-adjust it for your CRT.
 
I have shipped the chassis out today via UPS ground.
Please let me know as soon you receive and install it."

Oops. 

[Kevin Mullins]

  phew.... just finished reading through this one. 

[Numbski]

Well, the chassis got here.  Again.

Hook it all up, hooked the power up via the transformer - double and triple checked all of my connections, said a small prayer, turned it on...

Neck doesn't glow.

 

I.  Cannot.  Believe.  This.

 

I can see where they replaced the transistor that's up against the metal shield connected to the flyback.  It *looks* like it's properly insulated, but knowing my luck it isn't, and I just fried it.  Again.

[Numbski]

Nevermind.  For the first time in who knows how long, the chassis seems to be okay.  I say seems, because I hooked a computer up long enough to get video.  Somehow, mysteriously my Jamma wiring is now hosed.  No arcade boards will fire up, so I can't get a feel for the screen's geometry to say 100% certain that it's good. Man...

[grantspain]

meter jamma pin1 and 3 for +5v

[Numbski]

Okay, sorry for the slow response.

1 and 3 I get nothing.  2 and 3 I get +5 volts.  That's because I traced the ground wire from pins 1 and A, and they run to the connector for the coin door, which is currently not installed in the cabinet.  I don't think that's the problem, but I can jump those two to ground if it makes thing more clear.

[Pac-Fan]

Nah - I'm breaking out the heavy artillery next time.  I had already bought a super-insulated *BIG* screwdriver, and had copper tied to the ground on my nearest power outlet.  Next time I'm bringing in my jumper cables from the truck, clamping one end to the screwdriver, and the other to my water pipes.

That's why you got shocked. You didn't discharge correctly.  Earth ground/your power outlet/a water pipe has nothing to do with discharging a capacitor/picture tube.

All you need is a basic long insulated screwdriver with medium gauge wire clipped to the screwdriver and to the aquadag strap. No artillery needed.

[grantspain]

connecting this chassis to a pc is a sure fire way to kill it

how have you connected the rgb wires and do you get a white screen if you turn the screen volts up a little

[Kevin Mullins]

And a bad JAMMA input (RGB) should have nothing to do with "neck glow".
Sounds more like it just didn't turn on.

Did you pull the monitor back out of the cabinet to test it with the pc?

[Numbski]

No.  In fact, my Jamma wiring hasn't changed in this cabinet, ever.  It's the same wiring that was there when I bought it.  The neck didn't glow because it had no video signal.  I hooked up a PC with an ArcadeVGA card, and I got a nice, clear picture.  It's just the lack of Jamma that is the problem.

So far as earth not having anything to do with discharge, now you've just got me confused.  If my screwdriver being grounded to my nearest outlet isn't grounding the screwdriver, but clipping the wire to the cabinet which is in turn not connected to earth in any way *is*, that just doesn't make any kind of sense at all.  Sorry. :\

[Kevin Mullins]

The auqadag wire IS earth grounded...... if the machine is plugged in.

Discharging a monitor is the same as discharging a capacitor. (a really big one)
Which needs discharged between it's positive and negative sides.
In this case the tube is the positive side and any ground within the cabinet is negative.

So if your machine is unplugged from the wall and you discharged your monitor between the tube and an outlet "ground"..... then it probably didn't do much for it.

So basically it is simpler and safer just to say:

Unplug your machine.
Attach one end of your discharge tool to the auquadag strap. (since it's right there)
Then slip the other end up underneath the anode cup. (suction cup on the tube)

As far as neck glow...... that is actually heater glow, which typically is on as soon as you turn the monitor on whether you even have a video signal hooked up to it or not.
So it sounds odd when reading your description of events.
"Glow with PC hooked up, but no glow with JAMMA hooked up"
Should glow with nothing hooked up.
Unplug your video input (jamma) and turn the SCREEN voltage on the flyback up a bit.... screen should go white.

Correct me if I am mis-leading anywhere with this stuff guys.

[Numbski]

Please don't mistake my frustration as being an ingrate.  My frustration is running VERY high though.

Give me a few mins, and I'll turn that screen voltage up some.

[Kevin Mullins]

Oh we all understand the frustration I'm sure .... we've all been there at some point for sure.
Just gotta cover your understanding of the basics as much as possible, saves alot of headache sometimes.

[Numbski]

Alright, "in a bit" quickly turned into "in the morning".  Yes, if I turn up the screen pot, the screen turns white.

[grantspain]

white screen=no video input or blanking fault
unlikely blanking fault,either you have a plug off,video connected up wrong or your jamma video output is not working due to board fault or power supply

[Pac-Fan]

The auqadag wire IS earth grounded...... if the machine is plugged in.

Actually that is not correct either a lot of the time. Many times the monitor is completely isolated from any earth ground. (Because the last op converted it by cutting the ground strap to the frame, etc.) You cannot assume it is. Safest to assume not.

--> Your instructions however are spot on -- Anode to Aquadag is the ONLY way you can be sure you discharge completely and correctly. <--

In this case the tube is the positive side and any ground within the cabinet is negative.

Not quite correct. The inside of the tube (connected to the anode wire) is the positive, the outside of the tube, connected to the aquadag strap is the negative.

Assuming anything else beyond that (that the frame touches the aquadag strap, or the frame is grounded to a ground strap, or somehow connected to earth ground) is where people go wrong.


To the original poster: As Kevin said.. it's a capacitor.  Think a battery.  How does a flashlight deplete the charge in the battery? It discharges the battery by connecting a filament between + and - (and the filament happens to also produce light and heat).  You don't connect a flashlight to your water pipe to discharge it or make it glow.

Same principals apply to discharging a capacitor and picture tube.

Hope that helps.

[Numbski]

That helps a ton, actually.  I hadn't even thought about that fact.  The battery example is what lit up the bulb in my head.  d'oh.

You can't take two wires, and a battery, connect both ends to the ground (literally, like go outside and connect them to the ground) and expect the battery to discharge.  Too much impedence (I think???), but it *will* discharge if you directly close the circuit.

This is why I don't work in electronics for a living.

This doesn't, however, solve the issue of what's wrong with my Jamma wiring.  My boards are either all fine or have all gone bad together.  It's not just one.  I tend to believe something is hosed with the wiring.  I've traced out 5v and 12v, and R, G, B, S.  They all seem to be okay so far.

[Numbski]

So.  I got the original K7000 chassis back after being "fixed".  For the second time.

Since I know my Jamma loom has issues, and arcadevga works okay, I swapped chassis, hooked up my arcadevga, and was greeted to the picture below.

I tried adjusting screen pot on the flyback, h-hold and v-hold,along with brightness and contrast.  No picture though.

[Ken Layton]

Appears you're not getting a video signal.

[Numbski]

I'll continuity test my video lines when I get home.  Might as well test the video harness going to the chassis while I'm at it.

You can't see it from that picture, but it's pretty badly pincushioned too.

[Kevin Mullins]

How do you have the video SYNC lines connected?
Are you using a breakout cable from the ArcadeVGA?
Is it wired correctly?

As Ken said, it just doesn't appear to have a video signal at all.
(colors maybe, but no sync)

[Numbski]

I'll check when I get home, but it did work using the Wei-Ya chassis and the same arcadevga card.  If I recall, the connector on the K7000 goes R,G,B,Ground, (emptyx3-4), H-Sync AND V-Sync on one line.  Just from memory though.

That said, I *have* been cleaning up my Jamma harness trying to figure out why I get no video from those boards.  I suppose it's possible that I knocked the sync line loose from my ArcadeVGA breakout board.  I will double check as soon as I get home.  Have no idea what to do if I get video and the pincushioning remains.

[Numbski]

I'm home now.  I just tested continuity on all 5 lines coming off of the ArcadeVGA breakout board.  They're all good, R, G, B, Ground, and Sync.  I checked from the breakout board to the connector, and then all the way to the conductor traces on the chassis.  There's definitely line for signal.     

[Numbski]

Oookay, out of desperation, I hooked my SF2 board back up, and well - take a look:

It's worth noting that after all of this trouble - the picture is *STILL* too freaking narrow.  I don't know what it takes to get the geometry right.

[Numbski]

There's still got to be something up with the sync on this.  I just hooked up my PC, I get video, but I keeps wanting to roll top to bottom, like something is up with the horizontal output stage. (look at me talking like I have half a clue)

[grantspain]

this is one of the most confused posts i have ever seen,i cannot work out if you have a wei ya or wells chassis on your tube anymore

do you still have a resistor across your yoke?

the last pics show incorrect sync signal and too high brightness

rolling from top to bottom indicates missing vert sync

[Numbski]

Sorry for the confusion.

1.  I have 2 tubes now.  The 25" in my cabinet, and now a 27" that I converted.

2.  On the recommendation of Ken, I ordered a Wei-Ya.  It either came bad, or I damaged it, so I sent it back.

3.  While all of this was going on, I took my K7000 chassis back to the guy that "repaired" it the first time.

4. The Wei-Ya chassis comes back, so I install that back into my arcade cabinet.  ArcadeVGA appears to work, but the Jamma harness produces no video.  I begin sorting through my Jamma harness, putting various bits of wire through nylon split-loom ( http://cableorganizer.com/f6-wrap-around/ ), like all of the video lines, all of the player 1 lines, etc.

5.  I get a call from the guy with my K7000 chassis that it's ready to go.

6.  I swapped the chassis' out of my cabinet, putting the original K7000 chassis back in, which also required me to swap the video input connector harness (thus raising questions about my sync and my wiring).

So there you have it.  I have the Wei-Ya chassis sitting here, and the K7000 series monitor is "whole" again.  Sorta.

After reading your post, yeah - I remember from all of the videos I've been watching that it's vertical sync, not horizontal sync that is missing.  The thing that's confusing about that is that I've always used composite sync on this monitor.  At least so far as I'm aware.  The K7000 manual mentions having them split, but even when I bought the monitor, they were both run on the same line, and later on when I visited these boards I was told that was correct, so - WTF.  The Jamma harness has only one sync line, and I have continuity from the board to the chassis - so once again we're back to a damaged chassis?

It's worth noting that the dimmer a screen is, the more stable the picture is, which is why the last picture looks okay.  There's not much brightness to it, or "flash".  The "Street Fighter II' Hyper Fighting" Screen where "Hyper Fighting" flashes jumps around pretty badly, and of course in-game is crazy.  I took all of those pictures in succession in demo mode, no adjustments in-between.

Anyhoo - as far as I'm aware I can put the Wei-Ya back in and be done.  I guess I got greedy and hoped maybe the original K7000 chassis could be salvaged, and I could use the Wei-Ya on the 27" tube seperately.  There's no plausible way I can get that 27" tube into my cabinet without some serious hacking, and I think I'd rather build a new, smaller cabinet (candy-style) or buy a smaller cabinet and install that tube in it rather than try to shoe-horn a 27" in there.  I think this is a Dynamo cab? (the original TMNT 4 Player cabs, non-converted) - so unless there's a guide on doing that, I'm not sure I'll be trying it.

[Kevin Mullins]

this is one of the most confused posts i have ever seen,i cannot work out if you have a wei ya or wells chassis on your tube anymore

  I was just thinking the same thing......

First off, let's stick with ONE chassis, ONE tube and ONE wiring setup.
Stick with the 25" tube and the K7000 chassis and the AracadeVGA for now.

You've mentioned an ArcadeVGA "breakout board".
What is that?
Typically if using an ArcadeVGA your monitor wiring goes straight from the video card directly to the monitor, nothing in between. (plugged in just like a pc monitor)
There should be TWO sync lines coming from the video card, 13 and 14 I believe, that need combined creating the composite sync (single wire) at the other end.
So you should have 7 wires coming from the PC with two of them joined together making 6 wires at the monitor end. (composite sync)

I'm also unclear as to why you keep referring to the JAMMA harness wiring.
But I guess that's dependent on what that "breakout board" is.
Do you have video going from the ArcadeVGA to this breakout board which then plugs into the jamma harness or something? (like an I-Pac or J-Pac or something?)

Now the question goes back to exactly how and WHERE do you have the video wiring connected to the monitor itself? (which pins on the K7000)

Ignore the dimness of the picture until you get a solid and stable picture consistantly.
 

[Numbski]

Let's give you some pictures then.

Picture 1 is a picture of the VGA cable that runs to the ArcadeVGA, and the ArcadeVGA breakout board.

Picture 2 is the barrier strip I use as a "splitter" between the cabinet's monitor and speakers, and my various inputs until I buy a MultiJamma Proper.  If it's not legible, it's labelled "Cabinet Side" on top, and "Game Side" on bottom, the strip inputs are labeled "R,G,B,S,L,R"  The top side R,G,B,S are tied to my video input harness running to the K7000.  L and R currently are not hooked up.  On the bottom, I have my Jamma Harness' R,G,B, and S lines hooked up, and then the ArcadeVGA breakout board is also hooked up on bottom.

Picture 3 is my video signal harness hooked to my chassis.

Picture 4 is a shot of my Jamma harness with everything else.

Clear things up a little?  I just have to be careful not to have a Jamma Board hooked up while a PC is booted up.  I'm VERY careful in this regard, and intend to get a proper MultiJamma "real soon", like after I have known good video.

[grantspain]

interesting to note that video ground is not the same as your psu/jamma ground

[Numbski]

interesting to note that video ground is not the same as your psu/jamma ground

THAT is very interesting to note.  This thread has opened my eyes that ground != ground.  It never even occurred to me!  Crap.  How many "grounds" do I have in a cabinet?  Video ground, audio ground, 5v ground, 12 v ground, switch grounds...?

[Numbski]

I just walked over there and sure enough I've tied all of my grounds together.  I think I've got them split, but it had no impact on the picture.  Here's the grounds as I see them:

1.  AC/Wall outlet ground
2.  Ground coming from the PSU
3.  Video Ground
4.  Audio Ground
5.  Jamma/Switches ground

Which ones go together, if any?  Don't all of them eventually have to tie back to #1?

[grantspain]

how it should work is as follows.
ac EARTH(not ground) should go to metal frame work(such as coin door,cp) and the psu earth terminal only
video ground to video ground monitor input plug pin only
psu ground to jamma 1,2(a,b) and 27,28(ae,af)---switches---coin door
audio ground to speakers only

[Numbski]

Oookay, before you answered I actually got the picture stable.  Here's what I have:

The metal frame for the monitor is "video ground".  Tied to it are the video ground plug for the monitor,  the video ground line for the video signal, and the matching video ground for both my Jamma harness and the ArcadeVGA breakout board.  If I see what you said above properly, I'm mostly right, except that the frame for the monitor should actually be AC's "Earth", not video ground.  Right?

Sound is working properly, but I'll double-check that's correct too.  The only problems left then are that I have a weird top-to-bottom artifacting line on the left-side of the picture (not overlap though), and then of course as always, the picture is *still* too narrow.  I can fix that by changing the width adjustment cap, but it seems like that's not the right way...

[Numbski]

CRAP.  It's exactly the same as before I sent it out.  The geometry is hosed - the sides are narrower than the middle!

[grantspain]

which chassis,the wells?
anyway video ground should not go to the frame unless you want to blow the crap out of your game boards

[Kevin Mullins]

VIDEO GROUND SHOULD ONLY BE COMING FROM THE VGA CARD.... period.
It should not be tied to anything except VIDEO stuff.
There is a specific pin on the JAMMA harness for video ground, a specific pin on the video card for video ground and a specific pin on the monitor for video ground.
No "metal" stuff"... no frames .. no power lines ... etc.

And like grantspain mentioned...... separate those grounds.
Especially the video ground.
On your terminal strip where all your video stuff is connected you should have:
R, G, B, S, G .....with that ground being totally seperate from any other type of ground.

So is your ArcadeVGA "breakout board" actually the video amp from Ultimarc?
http://www.ultimarc.com/vidamp.html
Is it getting the required +5v supply from the video card? (pin 9 on the vga connector)

I've messed with one of those video amps on a project once and it just flat didn't work.
So you could very well have a bum amp.
I suggest trying to wire it up without one to first figure out where your problem is.
http://forum.arcadecontrols.com/index.php?topic=83104.0

Which version of the ArcadeVGA do you have?
(you really shouldn't need an amp with it)

[Numbski]

which chassis,the wells?
anyway video ground should not go to the frame unless you want to blow the crap out of your game boards

Yes, the Wells.  I'll make sure the frame is tied to AC earth and seperate the video ground from it.

[Numbski]

VIDEO GROUND SHOULD ONLY BE COMING FROM THE VGA CARD.... period.
It should not be tied to anything except VIDEO stuff.
There is a specific pin on the JAMMA harness for video ground, a specific pin on the video card for video ground and a specific pin on the monitor for video ground.
No "metal" stuff"... no frames .. no power lines ... etc.

And like grantspain mentioned...... separate those grounds.
Especially the video ground.
On your terminal strip where all your video stuff is connected you should have:
R, G, B, S, G .....with that ground being totally seperate from any other type of ground.

Understood, and fixing it as we speak.

So is your ArcadeVGA "breakout board" actually the video amp from Ultimarc?
http://www.ultimarc.com/vidamp.html
Is it getting the required +5v supply from the video card? (pin 9 on the vga connector)

I've messed with one of those video amps on a project once and it just flat didn't work.
So you could very well have a bum amp.
I suggest trying to wire it up without one to first figure out where your problem is.
http://forum.arcadecontrols.com/index.php?topic=83104.0

Which version of the ArcadeVGA do you have?
(you really shouldn't need an amp with it)

It's an older revision AGP.  I couldn't tell you off the top of my head, but the images I'm posting are actually coming from my SFII Hyper Fighting board, connected to the Jamma Harness.  The video amp was working pre-cap-kit, so I would be surprised if that's the issue, but I can take it out of the mix if it's a concern.

Off to take that monitor frame out of the video-ground mix.

[Numbski]

Are you guys *certain* that the frame holding the monitor shouldn't be part of video ground?

The reason I ask is that there's a metal ribbon strapped all around the back of the tube.  At one point, there is a black ground line that is tied to this ribbon, that is in turn hooked to the neck board of the monitor.  Is this *not* video ground there?  Without even hooking up the ground line on the video harness, I'm showing continuity from that ground line to frame.

[grantspain]

am i certain,well after 22 years of repairing arcade machines i am pretty certain

the monitor frame should be earthed,here is a good example of why it should not go to video ground;
when you discharge the anode to the dag(earth) which is connected to the frame where do you think all that very high voltage will go?

the video ground(jamma pin 14) should ONLY go to the ground of the monitor video input plug

[Numbski]

Not arguing - just having a very difficult time finding how on earth the monitor's frame is getting continuity to that video ground line.  It's nothing I've hooked up, that's for sure. :\

[Numbski]

K.  So I have the monitor's frame separated from the video ground.  I had to sever the ground line between the neck board and the ribbon running around the picture tube (wasn't hard, it was held together using a wire nut).

I'm not about to turn this thing back on without further instruction.  The ground wire coming off the neck board shows continuity to the video ground line, and the ground wire it was hooked to shows continuity to the picture tube frame.  This connection was there when I bought the cabinet.  I get the feeling that these two ends should be hooked to something, someplace, but I'm at a loss as to what.

[Numbski]

Okay, maybe this isn't as bad as I thought.  I pulled off the neckboard, and it looks like the prior owner (or the repair shop???) soldered two ground lines together at the top of the neck board, one going to the metal frame/shield on the chassis itself (video ground I presume???), and the other going to that metal ribbon on the frame, and THAT is what's tying the two together.  I can only presume then that it's safe to entirely remove the black wire running from the ribbon around the picture tube to the neck board, leaving only the ground wire from the neck board to the chassis.

Right?  Right???  Please?

Now here's why that doesn't make a bit of sense:

The Wei-Ya's chassis has a ground wire coming off of it's neck board too.  At the end of that ground wire is - a metal ribbon with springy connectors that look suspiciously like the one that this ground wire is hooked to, as though that one wants to do the exact same thing.

Either way, I'm not proceeding until someone gives me an all clear.  Something tells me that maybe video ground should *not* be attached to the metal sheild on the chassis itself, and this connection point is a coincidence, and not the actual cause, meaning that the two are interconnected on the chassis, not at this joint.

[Ken Layton]

What are trying to do, kill yourself?!

A k7000 neckboard has two heavy black wires soldered to the ground foil on it. One of those black wires goes ends in a "ring" terminal bolted to the metal frame of the monitor main circuit board where the big white resistor is mounted. The other black wire goes to the long braided spring loaded wire going across the back (black colored area) of the picture tube. Both of these areas must remain connected to the neckboard.

[Kevin Mullins]

Thank you Ken ...... I wasn't sure how to put that.

Put all that stuff on the chassis back together and leave it alone.

Your VIDEO GROUND is simply a single wire that goes from your video source, either ArcadeVGA card video ground or the JAMMA harness video ground, and from there it goes straight to the video input connector on the monitor.
You have the video amp in between, but the same principal applies.....the video ground doesn't stray off and connect to all sorts of other stuff.
Straight shot from the video source to the monitor.
Leave it at that. Don't make that part difficult. 

[Numbski]

I'm honestly not trying to make this difficult, thus why I did not turn the thing on.

When all of that is hooked up, the video ground is then tied to the frame on the picture tube.  You guys told me that was wrong, and I traced it to here.  I'll hook it back up that way, but it means that the frame of the picture tube is hooked to video ground.

[Numbski]

K.  Got it all hooked back up.  We have a nice, clear picture with completely hosed geometry.  What's next?

[Numbski]

If it's of any help, this is what it looks like without any video source, and the screen pot turned up slightly.  Notice how bright it gets bottom-right, and the pincushioning on the left.  Also, the artifacting lines top-to-bottom on the left remain without a video source.

[grantspain]

a bit scary some of this,problem is that you don't understand what we are saying mate.
video ground is only the signal input,the neck card ground is different(its an earth)-normally there is only one that connects to the dag but sometimes you have another that links to the frame,all depends on the monitor type

your next step is to post a picture of your screen with a grid pattern so we can see the geometry issues

[grantspain]

also i must add that although you may find this difficult and frustrating you are actually attempting to do things that many techs would not even consider.
we are all trying to help but you need to understand the basics first and more importantly safety aspects

[Numbski]

also i must add that although you may find this difficult and frustrating you are actually attempting to do things that many techs would not even consider.
we are all trying to help but you need to understand the basics first and more importantly safety aspects

I understand.  The two things on my mind when I went to bed last night were:

1.  Random internet people are both trying to help me fix my monitor AND keep me from killing myself.  I'm lousy at showing it, but I *am* thankful for what you guys have done here, which brings me to...

2.  Exactly how expensive shipping kegs of beer out are, because at this point that's what we're up to.

Anyway - I've re-posted the images below.  I've long thought about taking a course in electronics, and even bought an arduino board a month or two ago and started dabbling with that.  I swear until you mentioned it, I thought the terms earth and ground were used interchangeably, and that ground is ground is ground.  It all goes to the same place.  That battery comment finally put it together for me - and also brought back my studio recording days, trying to hunt down ground loops that cause speakers to buzz by having more than one path to ground.  Basically the arcade cabinet has 3 separate circuits going on.  There's the circuit that draws the AC mains, and has a transformer (the PSU) on it that creates our DC voltages.  There's another circuit that draws the AC mains, hits an isolation transformer and powers the monitor, and then the circuit(s) on dc power beyond the PSU.  I should have then realised that there were multiple ground lines right then and there - but again, for some reason my brain wasn't wrapping around this whole thing quite right.

From all indications, we have the multiple ground situation cleared up, and we have a clear image at least.

[grantspain]

now thats a good picture,i think the pincushion is being caused by the lack of width.
you must know by now that the width is adjusted using the width coil,what happens when you adjust that now?

[Numbski]

It moves in and out very slightly - not nearly enough to adjust it properly.

[Kevin Mullins]

Is that the only JAMMA board you have to test with?

Here is a Nokia Monitor Test program I use sometimes for testing monitors connected to my pc.
In other words....you should be able to connect your ArcadeVGA to the monitor and run this test from your PC to check the geometry and such as well. (instead of the jamma board)
Monitor Test

Check R43 which is right in line with the sync input, should be a 2.2K Ohm resistor.
Lower it's value and see if there is a change in geometry.
You can even short across it with a jumper to note any major change. (bypass the resistor)

[grantspain]

It moves in and out very slightly - not nearly enough to adjust it properly.

so you are back to the original fault which either a faulty width coil or a problem in the width circuit
unless of course this is a 20" chassis on a 25" tube

[Kevin Mullins]

unless of course this is a 20" chassis on a 25" tube

Good point ....

What is the P number on the main chassis?
Should look for something like a P447 or P538 or anything to that effect.

[Numbski]

I'm not at home, but I can say pretty emphatically that it's the right chassis.  I've had this monitor for almost 10 years - and it has worked properly the vast majority of that time.  Things only went awry when I went to install the cap kit.  The only thing that was wrong prior to that was that the picture was slightly too wide, in fact I have a picture of that too:



The image was slightly overscanned, and turning the width adjustment coil didn't appear to fix it, so I posted on these forums about a year ago, and Ken suggested I change out the width adjustment cap:

http://forum.arcadecontrols.com/index.php?topic=61421.0

So I ordered that cap, along with a full cap kit just for good measure.  That's when all of this began.

http://forum.arcadecontrols.com/index.php?topic=73028.0

Some time after this, I finally broke down, started calling around and found someone to repair the chassis, and turns out that I had shorted one of the transistors to the shield on the chassis, and that in turn had damaged some components, all of which he replaced for $70.  We got the wonky geometry, I fretted, ordered the Wei-Ya, took it back to the guy, who shipped it out to Vegas for repair, got it back and...ta da, we have the same picture again.  I'm not going crazy either - I got the same results hooking it to another tube he had laying around, so it's definitely not my tube.

Anyway...

My PC is running Linux - is that okay on the Nokia test?  I do have another board, a 6 slot Neo Geo, with only one cart at the moment, SvC Chaos.

[grantspain]

so you need to now checks all the cap values against the schematic in order to find if you have a wrong value cap in there

[Kevin Mullins]

My PC is running Linux - is that okay on the Nokia test?  I do have another board, a 6 slot Neo Geo, with only one cart at the moment, SvC Chaos.

Not sure about using Linux.... just try and run it on your computer without your K7000 hooked up, if it runs great, if it doesn't.... it doesn't.

You could try hooking the Neo Geo up just for reference that the image is still pincushioned.
Can't remember if it's the Neo Geo boards that have a slightly different video output voltage or something wonky to that effect. Was hoping you had some other generic JAMMA board laying around.

[grantspain]

snk require the vert and hor sync linked

[Numbski]

Actually - wait, I do.  I forgot, I have an Avengers board out in my garage that was installed in my Centipede cab when I bought it.   I'll grab that one and try it.

[Kevin Mullins]

Don't think that's standard JAMMA ... doesn't it require a Capcom to JAMMA adapter?

[Numbski]

I honestly don't know.  I just got home.  I thought it was CPS1 - thus Jamma, but it wouldn't be the first thing I was wrong about in this thread...

[Numbski]

P538

R43 does in fact measure 2.2k.  Jumping it now...

[Numbski]

Screen geometry retains the same distortion when R43 is jumped.

[Numbski]

NTest.exe will run under wine (just ran it on my mac), but I don't have wine loaded or configured on the arcade cab's PC yet.  If I had a BartPE disc laying around, I might be able to boot up and run it that way...

I think we can rule out the video source though - even when there's no signal, and there's just a white screen, the geometry is the same - the "whiteness" is even too narrow.

[grantspain]

i still reckon you have a wrong value component when you did the cap kit

[Kevin Mullins]

I think we can rule out the video source though - even when there's no signal, and there's just a white screen, the geometry is the same - the "whiteness" is even too narrow.

I have to agree with grantspain on double checking the cap values.
There's been known instances of a generic "K7000" cap kit having wrong values.
Especially when there are a few chassis that fall in that chassis family. P447, P538, etc.

I would check any cap labeled CAP LYT on this list against the ones you installed.
http://www.wgec.com/bom/P538.pdf

Double check that none are in backwards as well.
Might as well while you're looking at them.
(even though usually if they are they pop almost immediately)

[Numbski]

Will do - but probably not tonight or tomorrow night - it'll have to wait until this weekend.  Thanks for the pdf!