Domino Man issues: hum, black bar, and gfx issues

80scoinops

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Game was fully working, sat for a few years. Rebuilt the monitor, looks great, B+ is right at 120.1.

It has the original MCR PS in it, only thing I changed since I've had it was to remove the battery. No acid damage. Original light fixture is in the game but no bulb installed.

Game still fires up and plays fine, but it hums as soon as the game comes up and it has a scrolling horizontal black bar. What's the most likely culprit?

There are some minor graphics issues too, but it's tough to see with the scrolling black bar in the way. Tried reseating the harness edge connectors, no change. What's next? Clear the other issues first and go from there?
 
Game still fires up and plays fine, but it hums as soon as the game comes up and it has a scrolling horizontal black bar. What's the most likely culprit?

Any one of the three big caps on the transformer assembly can cause this.

Edward
 
Thanks!

Best source for ordering them? Bob? Just ask for a set of the three transformer caps for an MCR II game?
 
Thanks!

Best source for ordering them? Bob? Just ask for a set of the three transformer caps for an MCR II game?

Bob and ArcadeShop have the best price on the two electrolytic caps....I don't know if Bob has the big oil cap. Also, these caps are expensive...and other stuff can cause hum bars. Do you have another MCR game you can swap parts with?

Edward
 
Don't have one right now but might have one soon. If the next one doesn't have hum bars, where would you recommend starting with switching things out? Power supply board then transformer assembly?
 
Don't have one right now but might have one soon. If the next one doesn't have hum bars, where would you recommend starting with switching things out? Power supply board then transformer assembly?

I'd start with the transformer assembly....no other reason than that's what my gut is telling me.

A lot of things can cause a hum bar...big filter caps in transformer assembly, weak fuse clips, bad grounds (somewhere), weak connectors (transformer assembly, power supply, motherboard), monitor filter cap, something else in the room with the game...causing interference, or something on the same 120V wall line as the game (causing interference).

Edward
 
Thanks! Pulled all the fuses the other day and cleaned the ends and the clips, all the clips are snug. I'll work through the rest of the list and report back.
 
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