Galaga cabaret k4700 rolling and seeing triple

tblake05

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Check the video, I'm seeing triple and sort of a vertical rolling issue.

What's the deal? Is this a monitor issue or a game board issue?

Thanks!

 
that's a V. Hold issue, is V. Hold not adjusting? if you had a solder break either at pot or XY card header you would have vertical collapse
 
that's a V. Hold issue, is V. Hold not adjusting? if you had a solder break either at pot or XY card header you would have vertical collapse

I'll check. Didn't even try adjusting it. I don't like adjusting as no one would mis-adjust something before putting it into storage for an unknown amount of time. So I'm feeling like a component is out of spec.

But anyways, v-hold. Now I know where to look. Monitors are not my expertise. Thanks!
 
that's a V. Hold issue, is V. Hold not adjusting? if you had a solder break either at pot or XY card header you would have vertical collapse
adjusting vertical hold and it looks good…. But it still flickered and horizontal width needs to be adjusted. A little off screen.

I've seen flickering like this before and just had dirty pots so I think I'll dexit them. As it ranand warmed up, flickering stopped.

I haven't had much of a chance to look over the schematics, but What amplifies sound on this game? I have some serious hum from the speaker and as screens change, the hum changes frequency. I assume bad caps?

Now that I have a somewhat working game, I can start restoring the cab. :) neat game!

Thanks guys!
 

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amp is the MB3730A in the corner of the board

it's probably caps at fault though, they've been the cause of wonky sound for about 10 years or so now
 
It still sort of flickers and I notice the brightness going up and down on its own. Check the video.

As much as I hate inducing another problem, I feel the monitor could use new caps.

Thoughts?

 
It still sort of flickers and I notice the brightness going up and down on its own. Check the video.

As much as I hate inducing another problem, I feel the monitor could use new caps.

Thoughts?

The monitor can use new caps.

They weren't good ones. Nobody expected these things to be running in 5 years, much less 40.

Atari (per @andrewb) had greater vision, and used better caps.
 
It still sort of flickers and I notice the brightness going up and down on its own. Check the video.

As much as I hate inducing another problem, I feel the monitor could use new caps.

Thoughts?

that's just your phone camera ;)

K4600/4700 I would encourage replacing the Black Level pot on the signal board (and mount it on the solder side, not parts side, unless you're a glutton for punishment) and also the C621 cap. those can get a little intense with the picture jittering up and down (side to side in the case of Galaga) or it can create these snapping arcs and the whole picture will refresh weird.

otherwise all the pots on the neckboard and XY card could probably use a deoxit bath and wipe. and look into that amp issue!
 
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