Strange lines?!?

[havoc29]

Hi everybody....

I have, what i believe is a Hantarex MTC 9000...(pics)



But now, every time I turn it on, after 10/15 minutes, vertical lines start to appear...specially in light colors....

 


How can i fix it?

I've tried every knob (Shift, Amp, Freq..)

What does the Linearity Adl, the brightness present and bridge coil, do?

I really don´t understand much of TV's... i've read something about "jailbars"??

Can someone help me?

regards...

[SirPeale]

Looks like your filter cap is going.  IIRC it's on the neck, don't remember which one.

[Ken Layton]

Looks like your monitor needs a capkit.

[havoc29]

ok thanks....

Any TV repair shop will do?

What do i have to say to them?...


can I narrow the problem to one cap?

Thanks!

[grantspain]

with a monitor of that age any or all caps could be at fault,i had a similar faulty on a polo chassis-changed the usual suspects,but in the end every cap changed(electrolitic that is) to cure the problem.
just to add there was a resistor that caused a very similar fault on that chassis but i can't remember the position of it(i am sure its a 2 watt 33ohm at the very front of the chassis behind the flyback)-its many years since i worked on one of these,but i would certainly suggest getting a full electrolitic cap change.

[Rickn]

Rough guess, as I don't really know the monitor, but here is what I think.

The lines look relatively equal spaced apart, this tends to hint that one of the electrolytics off of the flyback that supplies B+ to the video circuit is bad.

Look for the normal signs such as "Bulged tops" on all electrolytics, leaky fluid, split top.

Good Luck

Rick Nieman
Rick@Niemandisplays.com
www,niemandisplays.com

[clanggedin]

If you know how to solder then you can cap a monitor. The kits cost under $10 and take about an hour to do.

A TV repair place will charge you labor and parts. Figure spending $100 to get it repaired by someone else.

I was really hesitant before I did my first cap kit, but it's not so hard. You just need to discharge the tube first, that's the scariest part of the whole thing.

[Rickn]

Just do not forget polarity, and be sure to put the right one in the right place.

Rick

[havoc29]

Thats what i thought... the caps...

this site has a caps kit i´m considering buying...
"Cap kit for MTC9000/9110. Contents, 19 of the most vulnerable capacitors. (C53 not included). All 105C. £5.56 (HAN007)"
http://www.coin.demon.co.uk/-video.htm#hantarex

Is it enough?

I've never tried to discharge a tube... and from what I've read... it made me a little (more!!) scared....
Not only because i can damage even more the crt, but because (mainly!) i can damage myself!!

who can i discharge "safely" a tube?? I've read of a method using a screwdriver (??!?!), but sound very dangerous!!

thanks everybody ...

PS: Sorry for my poor English!..

[tta583]

Some folks use a test clip on a screwdriver.  Some use 2 screwdrivers: one under the anode cap and another touching that screwdriver and the frame.  I just build one of these:
http://www.therealbobroberts.net/sb.html

I like to discharge mine at least 3 times.  About 3-5 minutes apart.  I also discharge the tube before I re-attach the anode.  Just clip onto the frame and touch the tip of your discharge tool to the metal ring in the hole on the tube.  I have had a nice “wake up” after caping a chassis when I went to hook everything back up.  Funny, seems to only happen with 4600’s.  Seems like every on there one I do will give a nice spark.  Oh well…

[SirPeale]

I like to discharge mine at least 3 times.  About 3-5 minutes apart. 

That's just silly.  Stick the probe under there and pop it off.

I also discharge the tube before I re-attach the anode. 

That, OTOH, is just smart. 

[havoc29]

I was thinking....

Could it be something to do with magnetic fields?

The computer and the sub woofer are right beneath the tube...I doubt the joysticks are to blame (Ultimarc's Mag-Stik)....

Could it be the degauss system?

The graphics cards?

Just guessing....

[SirPeale]

It *could*, but with that picture I'd bet $1.00 that it's your filter cap.  It's located on the neckboard on this model, IIRC.  There are two caps on there, correct?

edit: it's cap C205.

[havoc29]

Ok....

I'm going to buy the C205 Caps.... but just to make sure....

You are talking aboute this one?


(Neck board)

C205 - Radial Electr. Caps 10MF 250V

The big one on the pictures...

If i'm really carefull do you think i have to discharge the tube??

I only hope i don't break the monitor....anyway if that happens i can always buy a "new" 2º hand (at least) for about 130$ (postage included...)

[SirPeale]

I'm going to buy the C205 Caps.... but just to make sure....

You are talking aboute this one?


(Neck board)

C205 - Radial Electr. Caps 10MF 250V

Does it say C205 next to it on the silkscreening?

The big one on the pictures...

If i'm really carefull do you think i have to discharge the tube??

Personally, I wouldn't.  I'd just swap that one cap in the machine.  You don't need to discharge a tube to pull a neckboard.

If you're not comfortable doing things like this, I don't recommend it.

Ordering just one cap is going to cost you big bucks, unless you can find it locally.  Might as well just get the capkit.

[havoc29]

silkscreening? what's that?

I've looked in the manual, and that was the description of the C205, and that was the only one on the neck board...

i'm going to buy locally... but i don't know the price... must check that..

[SirPeale]

silkscreening? what's that?

When they make circuit boards, before they mount components on it, they use a process called silkscreening to label the components. 

So right by the cap on your neckboard you should see a tiny label that says C205.  Do you?

[grantspain]

if you look at this schem and trace the +190v and psu you will find the caps you need to change
http://www.freeinfosociety.com/electronics/schemview.php?id=2245
by my reckoning c205 is a def change,as is 34,45,53,54,56,201
good luck

[havoc29]

def change?

sorry but i'm really a newbie...

I don't understand the term....

[SirPeale]

def = definite.

[havoc29]

ok .. it's confirmed....

thats the C205...



grantspain - From what i can tell, the schem on that page is from a preliminary schem of the 9000...

I've found another manual of the MTC 9000, slightly diferent.. In the first one (form that page) the C205 caps is a 200v, on the second (the manual i found on the net) is a 250v, which is the one present on the board...

I will try to replace the C205 only to see if it works... if not... caps kit....

[havoc29]

ok...

replaced the C205 and C201... the problems remains...

guess I've to replace the other caps to....

[grantspain]

and check r36 on the neck card

[havoc29]

What does the r36 do?

[shorthair]

To reiterate the wisdom of others, here, if you're going to the trouble of replacing caps, and given the low cost of the kits, you might as well replace all of them and troubleshoot from there if need be.

[grantspain]

What does the r36 do?

sorry wrong resistor ,r216 which is .33 ohm is the one to check(r36 is on the polo chassis),this resistor is on the screen volts line

[Pac-Fan]

Rather than guessing at the caps, either replace them all (if you have jail bars, you probably need to replace all of them soon anyway) or at least find the right one the first time.  A quick Google Groups (Usenet) search using the terms: Jail bars Hantarex  pulls up as the first document the exact cap to replace:

Title: "List of bad monitor capacitors and symptoms"
...
Hantarex MTC9000
C34  22uf 160VDC  May cause shutdown of monitor.  May cause interference
bands on screen.  Common failure starting now!
...

I still suggest replacing them all, but if you must do just 1, at least try the one posted above.

When replacing, make sure you use NEW caps, not old stock as the capacitance values degrade even if not being used. Not doing all the caps at once will just end up taking more time in the end--you'll fix the first problem then have another one, or a dependence between multiples that should all be replaced.  A cap kit is $5 + $7 shipping from BobRoberts. If you need other stuff it's an even better deal, and worth the cost.


Full google thread link:
http://groups.google.com/group/rec.games.video.arcade.collecting/browse_thread/thread/3920d5b81eacc188/c5018d2f90244fa4

[havoc29]

Thanks everybody...

I guess i´m going to replace all of the caps, at least the ones on the kit...and i'll see what happens....

[havoc29]

ok.. now i'm going mad!!!

finally I've done the Caps Kit (including the C34, and the 2 ones on the neckboard)... and it didn't fix the vertical lines....(although now the color are more vivid, and the noise stopped.. )..

what could be the problem?

I've ruled out magnetic interferences. I've plug it in another room with only the MVS base. even turned off the wireless router!! (i'm desperate, i know..)

It doesn't matter if I plug the original NEO GEO MVS, or the jpac/computer, the result is the same...


It's strange because you have to wait a couple of minutes for it to appear...I don't know if it's because, it gets hot, or it builds up some kind of electrical charge...


Should i change that big cap (C53)?

Could the problem be the flyback/LOPT? Do i need a new one?

Could it be the monitor power transformer?

Do i have to ground it to the wall plug?


i'm almost giving up... any ideas? anybody?


Thanks

[grantspain]

you do need an earth on these chassis,normally an earth problem would cover the entire screen though not just 3/4 of it.
it is possible that the lopti could be at fault although rare
does this interference remain static or does anything affect it or does it change in any way?

[havoc29]

That's what i thought, it would affect the entire screen....


well... they wiggle a little bit, not much, and are affected by the movement on the screen..

It's hard to explain, but with the movement (of the game) and the change of the colors, on the screen , they kinda move...

you can see in this pictures... especially the neo-geo logo...





I haven't tried replacing the r216 resistor...

I've read something about "herringbone effect", but i don't think its same problem..

I've searched everywhere on the web, and i couldn't find a similar problem...even the guy who sold me the cab, doesn't have a clue... and owns an arcade place....!!

[grantspain]

what happens when you disconnect the video input and turn the screen volts up,do you still get this problem?

[havoc29]

ok.. when you say to turn the volts up, i think it's that knob on the flybak, under the focus one, the manual says it's the brightness...

so I did that... and the problem persists... 




So it doesn't have nothing to do with the video input...right?

[grantspain]

have you changed that resistor yet??

[havoc29]

Not yet.... i think its the next thing to try....

In the manual they say the r216 is a "METAL OXIDE RES 1E 5% 1W WK4".

What that means? if i give this description at the store, they will understand it?

Did some research...

Is this the one?

METAL OXIDE RESISTOR 1W 1R



This is part of the schematics ..

[grantspain]

any electronics store will know what a 1watt 1r(1 ohm) metal oxide resistor is

[rockin_rick]

Metal oxide resistors are usually 1% tolerance, and are often green colored, rather than tan.  Of course, these are not hard rules...

Rick

[havoc29]

 

replaced the r216 resistor... and still the same result....

I don't know what else to try!! I even disconnected the degauss system.!!

I'm gonna give up....

I'm going to try to buy another "new" (2ºhand) chassis, from the guy who sold me the arcade...

I don't think the problem is in the tube itself.... but somewhere on the chassis....

Any more ideas? anybody?

What really bugs me its that it takes a couple of minutes for the vertical ghost lines to appear....

PS: Can i use another kind of arcade chassis with this tube??

[grantspain]

i can phone my buddy at hantarex tomorrow for you-don't panic

[havoc29]

You have a friend that works at Hantarex? That's cool!!

Thanks!!!