X-Men voltage issue

AtomicBomb

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I have a 4-P X-Men board that is unhappy at normal voltages. If I run it around 5V, I get square graphical glitches all over the screen. As I push the V up, it gets better. All of the problems disappear around 5.6-5.7V as measured at one of the pins of a socketed EPROM. I have tried this with two different power supplies with the same result. I'm sure this isn't great for my board. What should I start looking for?
 
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Is there any corrosion anywhere, or oxidation on a chip's legs? The fact that it clears up when higher voltage is applied makes me believe that there is some heavy resistance somewhere and only by using more "force" are you able to get the actual +5V that the board is asking for.

Though I will defer to more knowledgeable folks out there as this is just my logical guestimate.
 
Still having this issue, but it is getting worse. Need to push the V up to 5.75ish now.

To answer above questions:
The board is very clean. No obvious corrosion but I cleaned the socketed roms anyway. No real change.

I'm measuring V from the Vcc pins of socketed roms. My thinking is that these would endure the most Resistance. These are where I am measuring 5.7 V. Measuring at the power supply, I find that it is pushing .1 or .2 higher than that.

I also checked the filter caps, all seemed fine. Is there a VR or something on this board?
 
had a board once that I had to turn the power supply all the way up to get it to run
board came from a saltwater environment (Martha's Vineyard) and had lots of resistance that one could see all over the traces but it did work when the power was turned up

think its curtains for your board although maybe if you had an oscilloscope, you might be able to track down some sort of problem area not seen by the naked eye

just for fun, measure the +5 volts before and after the connector and see if there is much of a discrepancy. hopefully you will see 5.75 on the wire side vs 5.0 on the board and can replace the pins inside the connector there as they can lose their "grip" and not allow enough electron flow to properly operate the game good luck
 
There is a little loss across the JAMMA harness, but I was measuring V @ a socketed chip. I figured that would have the highest amount of loss on the board, and it's still super high there. As of now, I'm having to turn the V up so high that I'm starting to get sprite errors just to get rid of the white/multi-colored boxing in the background layer.
 
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