Noob with dead monitor plz help

[b3dr0ck]

Look what I found.

I tested for a short.  I connected my multimeter - 1 probe to the metal railing of the monitor casing, then the other probe to one leg of the HOT.  It read 0 resistance, a complete circuit - thus shorted.  (Mine doesn't have the continuity test - no beep)  I tested the middle leg, and the far outside leg, they all read shorted.

So ... what would short the HOT?

[grantspain]

sometimes they just blow for no reason,other times it can be the flyback/shorted cap or even a tube problem

you need to read from the flyback shield to the centre leg

[b3dr0ck]

The "flyback shield", is that the aluminum cover that the HOT is mounted to?  What should it read to the middle leg?

[lilshawn]

This is an Ultracade it has a VGA output

the ultracade computer has a dongle that connects to the parallel port on the computer that tells it what resolution to run at. (standard resolution or medium res) if it has no dongle it will run at VGA.

you should have a standard res (15k) dongle attached to the port for use with this monitor.

[b3dr0ck]

There's a loopback plug on the parrallel port.  If I remove that, (and the cable connecting the vga port to the USBLinx) I can plug a standard VGA monitor in.  This is how I've done all the work on the Ultracade stuff to this point.  It works.  I just don't have a VGA monitor that is 25" 4:3 (and dont think I'll find one).

http://forum.arcadecontrols.com/index.php?topic=108697.0

I'm still going to fix this monitor. (or get it fixed)  So at this point, it looks like I'm gong to have to pull it out.  I just want to make sure:
1) the HOT is blown
2) taking it and getting it fixed is better than buying a k7000 chassis, and just replacing the chassis

If those 2 are true, then I just need to find a place to do the repairs.  (I'm still asking around)

[grantspain]

http://www.arcadecup.com/

[lilshawn]

if you can still find a local repair shop, it likely will cost about $100 to fix, which is't too bad. still cheaper than replacing it.

with some practice you could fix it yourself, and it would cost $20 or 30...but if your'e shy about high voltages it would be better to have someone do it for you.

but like mentioned before, this chassis CANNOT be plugged directly into the outlet, it must run through a transformer to isolate it. so if you do take it someplace for repair then be sure to mention it. you don't want to get dinged a bunch of power supply diodes and the regulator if they kill it that way first. (which may be fine otherwise)

I just don't have a VGA monitor that is 25" 4:3 (and dont think I'll find one).

in all but the older 7000/7500 type units the the dongle is useless.

unless it's for a lightgun game requiring CRT for gun signal timing, we are converting everything to LCD or Plasma displays where possible. I haven't built my ultracade up yet, since i just got a computer up and running, but i'm considering a 42" LCD since I can get one for what a new 27" is going for these days.

[b3dr0ck]

Basically - you're right, I think I should just put a VGA in, or something awesome like a 42" LCD.  The issue is the cabinet, will only fit something smaller right now.  Maybe in the future I'll move it to a large cabinet.

I'm thinking I'll need the WGK7000 for another repair in the future.

Not sure if you noticed my other thread, but I've got the computer up and running with all of the games packs on my ultracade (its the Hyperware version) with a new motherboard/CPU, and a new PCB on the old HDD - same RAM, not connected the CD-ROM.  I have to reboot the PC 3-6times, (soft boots too) and then it comes up.  So odd, I'm not sure what Joshua OS is doing or if the MBR is partially corrupted.

Anyway, at this point, I'm going to discharge the monitor, and remove it from the cabinet.  I might replace the flyback, and HOT myself, but since I don't even have a soldering iron yet ... I'm going to approach that very slowly.

[boardjunkie]

Mame looks like crap on a VGA monitor. Since most games are std res, yer really better off with the WG monitor. Its a simple problem and won't cost much to fix.

[b3dr0ck]

$150 at Arcadecup.com that seems like a lot to me, when I can get a flyback repair kit for $28, or I can buy a used chassis on ebay for $40.00.

If I had to guess, I'd say it's the flyback.  The top of it looks off to me, no one has noticed the pic, so I don't know.  In any case I'm pretty sure the HOT is shorted, so something had to cause that.

[lilshawn]

If I had to guess, I'd say it's the flyback.  The top of it looks off to me, no one has noticed the pic, so I don't know.  In any case I'm pretty sure the HOT is shorted, so something had to cause that.

i concur. looks like its arced out of the top to the core.

the flyback and HOT for sure...maybe more.

[boardjunkie]

I stated previously that the plastic case horiz output transistors used in the 7000's are not as robust as the "bottle cap TO-3 case ones used on earlier monitors. The can, and will, fail because of this. Nothing has to "cause it". I've seen it dozens of times during my tenure as an arcade machine repair tech. Same goes for the plastic case IC voltage regulators. They fail often compared to the discrete reg circuits used on earlier monitors. Its just the way it is.....

If in doubt, just shotgun the whole horiz section. Replace the flyback, horiz output, retrace tuning cap.

If I had one of my 7000 monitors here, I'd say just send me the board and I'll repair it for you. But I can't do it without the tube/yoke to verify proper operation. This is really routine stuff for a 7000.....

[b3dr0ck]

Just curious - could rapid temperature cause (expedite) the failure.  The cabinet was shipped on the back of a truck in open air.  It was about 32degrees, maybe a little colder.  So it was outside in that for maybe an hour.  Then taken off the truck and immediately plugged up and turned on.

I do recall smelling something like it was burning.

[lilshawn]

I've transported a machine in -40. Literally there was a layer of frost forming on the glass from the warm moist inside air.

Other than letting it warm up, I haven't experienced any issues with it.

[b3dr0ck]

I've pulled out the monitor and chassis from the cabinet.  I discharged the monitor (there wasn't a charge though).  I'm seeing signs this board be has been worked on before, and I'm seeing odd stuff, does this look right to you?

1.) Does the aluminum shield need to screwed down.  There a screw missing to the side bar, and the flyback.  Are those needed?
2.) The neckboard is attached with some black rubber tar like substance.  Is that normal, shouldn't I be able to disconnect the neck board?

[lilshawn]

I've pulled out the monitor and chassis from the cabinet.  I discharged the monitor (there wasn't a charge though).  I'm seeing signs this board be has been worked on before, and I'm seeing odd stuff, does this look right to you?

1.) Does the aluminum shield need to screwed down.  There a screw missing to the side bar, and the flyback.  Are those needed?
2.) The neckboard is attached with some black rubber tar like substance.  Is that normal, shouldn't I be able to disconnect the neck board?

yes...all normal. they add extra resistors and diodes and jumpers to fix issues after the boards go into production. it's factory...no biggie.

1:) not really, if it makes you feel better screw them down.
2:) yes, it's just silicone, it's just keeps vibrations from knocking it off.

[b3dr0ck]

Are these the solder points for the Flyback?

[MonMotha]

FYI, a possible reason for the unusually high line voltage at the monitor input is that many Midway cabs have several input taps on the giant transformer (which is the iso for the monitor and also sometimes powered other things in the cabinets).  By default, most were wired for 110 in/120 out.  Sadly, many (such as MK2 and I think NBA Jam) don't have a 1:1 option, so the best you can get is either ~110V out (set for 130 in/120 out with 120 actually going in) or closer to 131V (set for 110 in/120 out with 120 actualy going in).  On the upside, if you live in Europe or another 220-240V land, there are suitable taps for that, too.

if input voltage is a big concern (sounds like it probably isn't too bad), you might consider replacing the transformer with a true 1:1.

[lilshawn]

Are these the solder points for the Flyback?

yes...and the 2 others the same size under the arrows.

[b3dr0ck]

For right now I have a LCD flat screen in the cabinet.  I don't know how long it's going to take me to get the monitor back up and running.  Did I ever mention the fact that I don't even have a soldering iron.  That's probably not a good sign.

I'm not sure about the resolution of the VGA monitor, everything looks a little grainy, I don't know maybe Boardjunkie put that in my head.

I'm going out tomorrow to look at buying 3-4 more cabinets,  and some jammas - so ... I'm committed to my new hobby.

[boardjunkie]

When its cold out, don't *ever* just bring the (insert whatever electronic device here) into a warm environment and power it up. Condensation forms and damage ensues. So, it prob'ly worked just fine when it was sent out and you caused the damage by powering it up before letting it acclimate.

[b3dr0ck]

It was snowing a little

[lilshawn]

ta da!

[b3dr0ck]

So I scored pretty big today, I got 2 - 25" WG monitors with the chassis included.  Supposedly they worked, when they were pulled a year ago - or so.

The neck board was off, but I plugged them back in.

I decided to test one out on my cabinet.  I connected the power, and the the video inputs.  I turned on the power, and the PC ... and ... nothing

Checked the power at the plug 128vac
Checked the fuse - fine
Checked the power on the back side of the fuse 128vac

(nothing is simple)

I've got the serial (parallel) low res adapter on the PC, and the dongle from the VGA to the VGA on the USBlinx.  (you know this, but just to illustrate) When you boot a PC there is a black screen with white letters that shows the POST - this is before the ultracade stuff boots (the OS). 

Now on a low res WG k7000 monitor in an Ultracade, will the monitor show the PC post? 
Or does the OS have to boot before you see anything on the monitor?
Shouldn't I see or hear something on the monitor to know it's working, even without video input?

[lilshawn]

No, with the dongle and router through the usblinx card, the usblinx will cut the sync line off until the software is up and running, as often boot screens are vga in nature and can damage standard and medium res monitors.

[b3dr0ck]

So I gave this another shot.

I connected a monitor that I was told was good, same type monitor 25" WG K7000.  I got the ultracade to boot, miracle, and nothing on the newly connected monitor.

I have the dongle from the motherboard to USBlinx, and the serial adapter on the parallel port.

The chassis has power, it's getting 129vac on the backside of the fuse.  I see no glow in the yoke, I hear no crackle in the tube.  Can I expect to see, what would I look at next.

[b3dr0ck]

OK - not sure if anyone is still reading this but,

I connected another monitor (#3) that I know fer sure was working out of another cab.  I used the existing power from that cab, and just connected the video input.  It gets signal, and looks right.

Without the video signal you can feel the static electricity in the tube, (a way to tell the tube is getting power?).

Not sure what this proves, I guess
 - the usblinx, and the cga video output works, and the wiring is good

This does not prove the Isolation xformer is working properly - its putting out about 129vac, but thats sounds acceptable and norm for a midway cabinet

I think I may move the monitor over to the cabinet, I'll just have change the mylex plug on the input power

[coliveira]

Alright, I know you've read my other post (thanks for the positive comments), so I'm not even going to try to BS you.  You know a LOT more than me already!  A few things though:

1.  Give soldering a chance.  I didn't even do it correctly and it still solved my problem.  Really, you have nothing to lose.  I saw some of the videos on youtube and it really looks like someone that knows what they're doing could easily bail you out with solder suckers, etc. as long as you didn't go crazy.  I'd take a pic or two beforehand to give them an idea of what it looked like originally in case things do go awry.

2.  Don't forget about the scientific method.  It sounds like you've got several monitors that are pretty similar.  Are the parts interchangeable?  If so, you could try swapping them out and recording your results on paper.  You might notice patterns of what works and doesn't based on the parts being used.  Might help you hone in on the problem.

3.  Always check your assumptions.  You know what they say about assuming...  Honestly though, it's probably the only 'real world', practical advice I got in college.  Whenever I'm stuck against something that I don't think should be a problem I always start with my assumptions.  Usually I find something I've taken for granted that I never would've noticed otherwise.

4.  I think my monitor is VERY similar to yours.  It's not only a WG7193 that was working when I bought it but not when I got it home (at least properly), but I'm pretty sure it's also been an Ultracade at some point (at least that's what the burn in on the tube tells me)!  Feel free to ask me to confirm any results you get on voltage, continuity checks, etc.  Also, our wiring might be pretty similar too.

In the end, you'll get it!  BTW, I respect that it seems that the journey is just as important as the destination for you.  My wife and friends think I'm crazy for how much effort I've put into this damn thing, but I keep trying to explain how much fun it is to learn about things you had no clue of before...

Best wishes and good luck! 
Chris