Super Mario odd color voltage

Sectorseven

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So the green on this Vs. Super Mario I have is off. First I swapped monitors to see if that was the problem, but it didn't solve it.

I measured the green color voltage on the PCB (pin 10 I believe) and it measures a little over 8 volts, which for a Nintendo board means practically no green, correct?

After a few minutes, the voltage will suddenly drop to practically 0, and the screen is just filled with green. All the color pots on both the monitor and board have very little effect at this point.

Got a couple odd readings on some transistors in the green circuit, but I figured it was because I was testing them in circuit.

The roms all check out fine, so where should I start looking next?
 
What PPU chip are you using? I know the PPU determines the color pallette of the game and yours may not be the right one.

If that's not it, I'm all out and of no help. :)
 
PPU is
RP2C04
0004
4L4 32

Has a Super Mario sticker on the heat sink, so I assume it's compatible.
 
PPU is
RP2C04
0004
4L4 32

Has a Super Mario sticker on the heat sink, so I assume it's compatible.

Yeah, you have the right PPU. It seems like a board issue with the Green color. You could try reseating the PPU or even the chip set. You never know.

Vs. boards are known to have various issues whether it be color, sound, one side not registering, etc. I have had all of them in the past. Luckily, there are a lot of these boards out there for sale that work.

I'm not sure how you'd go about fixing your specific issue, but if all else fails, you can just buy a replacement PCB. An empty PCB usually runs around $30-40 shipped depending on who is selling.
 
You could try reseating the PPU or even the chip set. You never know.

Sound like this would solve your issue, you may have a bad PPU too. Do you have another Vs. board to swap your chips & PPU to see if that solves your issue?
 
Tried reseating the PPU, but no change. I was under the impression a bad PPU would really screw up the colors, where as mine is just subtly off, and after a few minutes suddenly gets real bad. It's always in a playable state though, just real ugly to look at. I'll take some pictures if it helps clarify things.

Unfortunately I don't have another PPU to swap in, and I don't really want to put any money into this. Vs. Super Mario isn't a personal favorite of mine, but I hate it when I don't know what's wrong with a game.
 
PPU problems can be very odd, but I would like to see you put your PPU and chip set into another Vs. board just to eliminate that the PPU or roms are the issue. Is there any corrosion on your board? The fact that it get worse after it's on for a few minutes make me think you have a bad PPU socket or a bad transistor for the green color.
 
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The battery holder was hacked up at some point, but I don't see any corrosion on the board. Looks like there's 3 transistors in the green circuit. I was too lazy to desolder them for proper testing, but I will if I have to. This is all based on an MDS-02 schematic I found. My particular board is an MDS-04. Hopefully there isn't a huge difference.
 
This is just an observation and it could be perfectly normal, but here's what I've gathered:

All the pins on the PPU seem to putting out a constant voltage even as the on screen colors fluctuate.

Pin 7 on LA6324 at position P1 (green) spikes way up from 0.8 to about 11 volts as the voltage on pin 10 (color green) drops.

Pin 8 on LA6324 at position P1 (red) always sits at about 10 volts

Pin 8 on LA6324 at position P3 (blue) also stays at about 10 volts.

I can actually press down on pin 7 when the screen goes green and it will momentarily fix the deep green problem. The standard over powering red still remains though.

These chips trace back to the PPU, which as I said remains constant.
 
Ive been having color issues with my vs. Smb as well. I can fix it with about 10-20 minutes of making adjustments on the board and monitor neckboard but if I leavethe game sitting for a few days the colors are all f'ed again. No clue. It's either this board or the chips. Doesn't happen with other games. I need to try my chips in one of my other boards but I hate working with em, lol. Always afraid I'll break a leg.
 
The pictures don't really do it justice, but here's a rough idea of what it looks like:

This lasts for the first few minutes when the green voltage is high


And this is after the voltage drops
 
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