Punch-Out!! power supply question

Kid Dynamite

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So I received a PO boardset that supposedly was fully working (I trust the seller on this one) and it has some minor graphics glitches and occasional distortion pops during speech in my PO cabinet. My 5+V reads 5.08 right now at the edge connector but I'm wondering if a slight adjustment could fix the problems. I have another boardset that works perfect at this voltage but I'm trying to find a voltage that works for both.

I took the cover off of the PS and found two pots, one marked "VR1" and the other "VR2". Which of these pots would get adjusted in this case?
 
So I received a PO boardset that supposedly was fully working (I trust the seller on this one) and it has some minor graphics glitches and occasional distortion pops during speech in my PO cabinet. My 5+V reads 5.08 right now at the edge connector but I'm wondering if a slight adjustment could fix the problems. I have another boardset that works perfect at this voltage but I'm trying to find a voltage that works for both.

I took the cover off of the PS and found two pots, one marked "VR1" and the other "VR2". Which of these pots would get adjusted in this case?

Not sure off the top of my head but at 5.08v I think you should be fine.
 
So I received a PO boardset that supposedly was fully working (I trust the seller on this one) and it has some minor graphics glitches and occasional distortion pops during speech in my PO cabinet. My 5+V reads 5.08 right now at the edge connector but I'm wondering if a slight adjustment could fix the problems. I have another boardset that works perfect at this voltage but I'm trying to find a voltage that works for both.

I took the cover off of the PS and found two pots, one marked "VR1" and the other "VR2". Which of these pots would get adjusted in this case?

Edge connector is not as good as measuring at the chips. What is the voltage at the chips??
 
Which chips? Any chips?

Just about any of the 16 pin chips and usually just across from pin 1.

Just plant the black lead to any ground on the board and probe (carefully to touch one pin at a time) various chips. Sometimes the farther you get from the edge connector the voltage will drop.
 
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Just about any of the 16 pin chips and usually just across from pin 1.

Just plant the black lead to any ground on the board and probe (carefully to touch one pin at a time) various chips. Sometimes the farther you get from the edge connector the voltage will drop.

Thanks for the tip! I checked that and there's only a -.02V difference at the chips to all distances. I've tried voltages at the edge connector of 4.97 - 5.25 and I get the same problem at all these levels. Where should I keep the power supply at theoretically for Punch-Out!!?
 
Thanks for the tip! I checked that and there's only a -.02V difference at the chips to all distances. I've tried voltages at the edge connector of 4.97 - 5.25 and I get the same problem at all these levels. Where should I keep the power supply at theoretically for Punch-Out!!?

I set most everything to 5.08 to 5.15 at the chips.
 
5.01 should be sufficient, I've seen a few games shockingly (newer ones) run fine at 4.9. I personally would aim for 5.15 at the chips on a Nintendo board though.

I've heard people say these power supplies are a nightmare to re-cap. at 30+ years old, I think they're probably due now yeah?
 
I've heard people say these power supplies are a nightmare to re-cap. [...]

They are not :)

The only important thing is to use High T°, low ESR caps and not the "usual" cheap caps ;)

In addition, don't forget to use a 100uF 35V in place of that 47uF 35V for C8. And don't touch the VR1 pot (overcurrent pot): only VR2 tunes the output voltage
 
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