problems with WG 19K-7203 monitor

[vet300]

I have a pretty well brand new monitor that I installed into a Joust cabinet, and hooked up to a computer through an arcade VGA card, was very dim at first, so suspected the 1V output from the card wasn't enough for the monitor.  I added an amplifier to step up the voltage to 4V, but it made no difference.  I was unable to get sync with the amplifier card as well- I had hacked a VGA cable originally, and sync worked well on the negative H and V inputs.  Did not work with composite.  While adjusting the monitor for brightness and colour, I heard a little "pop" and now the screen is all red with white lines across horizontally going from bottom to top of the screen.
At first the monitor showed the windows desktop, just in red, but now all I have is a blank red screen with white lines. 
I have an identical monitor (WG 19k-7203) purchased at the same time that is in a Robotron cabinet at work. This computer works fine on it, with the normal amount of brightness, and no amplifier attached.
Both of these monitors were purchased from Happ about 2 yrs ago, brand new, and the one in the Joust machine wouldn't have more than an hour on it- it's just been sitting in the cabinet unused.  It worked fine on the boards that were in there before I started the MAME project.
I am pretty well a noob at monitor repair, but can find capacitors etc. and replace them if necessary- I'm just no good at troubleshooting this stuff.
Thanks for your help,
Sean Egan

[grantspain]

can you get photo of the screen,to me it sounds as if either the colour decoder ic has gone or the red drive transistor is shorted full on
i guess you have rechecked you vga lead for any shorts or breaks using a multimeter

you could always see what happens if you disconnect the red signal from the avga card

[vet300]

I got a picture of the screen, but it is 2.73 MB, so it won't let me upload it.  Basically, it just shows a totally red screen with white lines across it.  I get the SAME picture if nothing is hooked up at all.  I was going to try a picture without the red line attached, but the screen powered up started getting bright and flashing/flickering, and I could smell ozone, so I powered it down for fear it was going to blow up.  It's definitely a monitor problem- I have an identical monitor in another machine, and it works fine with the cable attached.

[grantspain]

what i am trying to work out is if these lines are flyback lines or generated lines,without see a photo i can not say-i am leaning towards the decoder ic,it should be something like a lm1203 on the neck card
another thing you could try is removing the red drive transistor

[vet300]

The picture won't go through- is there an email I could send it to?
thanks,
Sean

[gokun]

upload the pic to http://www.imagevenue.com/ then copy and paste the appropriate link in your thread. Their max file upload is 3mb so that should be enough to get it uploaded for ya.

The picture won't go through- is there an email I could send it to?
thanks,
Sean

[SirPeale]

...or reduce the size of your picture.

...or make your camera take a smaller picture.

[vet300]

Yes, I thought of that, put the settings down to 640X480 to take a picture of it again.  Now it's going directly into flashing/flickering mode 2-3 seconds after power up.  I decided to video tape it, thought it would give more information, but now we're looking at a 35Mb file...

[vet300]

I was able to upload the video to 4shared.com.
You can access it through this link:
http://www.4shared.com/file/65228054/4d0b4e8d/DSCF0241.html

There is no video source attached to the monitor at all when I turn it on.  I turned it on, then off, then on again for a few secs. for you to see what it does.

Thanks for all your help!

[SirPeale]

It appears you either have a tube short or the red drive transistor on the neckboard has gone bad.  Check the transistor first (since it's the easiest test).  Failing that, find someone with a rejuvenator to test the tube.

[vet300]

So specifically you're talking about transistor Q802 here?

[grantspain]

q711 on the neck card