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MVS Puzzle De Pon Graphic corruption. Which chip Do I replace?

Jinx

Jinx

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Hey All. Picked this cart up on ebay fairly cheap (20-ish bucks, sorry If i bidded against ya!). Was hoping it would be an easy trace fix but I've gone over each pin with a multimeter and they all go to some place (chip/rom/via that goes to a chip). The board looks clean. No rust, no corrosion, no broken solder joint or traces (3x magnifier) that i can see. so I have to assume it's a chip issue? Which chip would be the most likely culprit, or do i need to remove them both/all and check them? (Only pictured char board as I figured it wasn't a program issue). You can see the teeth are very clean and I tried this in 3 different slots and the same result every time.

Also I'm no pro on the chip numbers, what size mb wise would be needed to replace these? I have a few roms on hand for repro snes/genesis personal carts I was going to make and would be awesome if they were just a drop in replacement (vs an adapter board and smaller chip)
 

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Last edited:
Since you're already removing chips, if you're interested, converting this to R is pretty simple.

It's just two roms:

235-p1.p1 in place of 202-p1.p1
235-s1.s1 in place of 202-s1.s1
 
Jinx said:
Hey All. Picked this cart up on ebay fairly cheap (20-ish bucks, sorry If i bidded against ya!). Was hoping it would be an easy trace fix but I've gone over each pin with a multimeter and they all go to some place (chip/rom/via that goes to a chip). The board looks clean. No rust, no corrosion, no broken solder joint or traces (3x magnifier) that i can see. so I have to assume it's a chip issue? Which chip would be the most likely culprit, or do i need to remove them both/all and check them? (Only pictured char board as I figured it wasn't a program issue). You can see the teeth are very clean and I tried this in 3 different slots and the same result every time.

Also I'm no pro on the chip numbers, what size mb wise would be needed to replace these? I have a few roms on hand for repro snes/genesis personal carts I was going to make and would be awesome if they were just a drop in replacement (vs an adapter board and smaller chip)
Click to expand...
what size mb wise would be needed to replace these?
check the rom file size.....

1725294627569.png

27c800
 
nem said:
Since you're already removing chips, if you're interested, converting this to R is pretty simple.

It's just two roms:

235-p1.p1 in place of 202-p1.p1
235-s1.s1 in place of 202-s1.s1
Click to expand...
thats interesting thanks
 
pierpa86 said:
what size mb wise would be needed to replace these?
check the rom file size.....

1725294627569.png

27c800
Click to expand...

Since I've never made a NEO convert/repro cart. is this a case of 'if it fits it ships' kind of thing? i.e. if the pins match and the size is big enough the chips on the cartridge aren't expecting any specific size? and I'll assume if I only have double that size I could just double up the data on the rom like I would do on a nes/snes cart?
 
nem said:
Since you're already removing chips, if you're interested, converting this to R is pretty simple.

It's just two roms:

235-p1.p1 in place of 202-p1.p1
235-s1.s1 in place of 202-s1.s1
Click to expand...

Is R like an enhanced version? It's just the program roms that change? Interesting. I guess once i replace a single rom on a cart than any collectable value is toast at that point, so why not?
 
I want to convert my Puzzle de Pon to R. Would an M27C4001 be a suitable replacement for the 512Kb P1 rom?

20250201_104749.jpg
 
pierpa86 said:
27c4001 dip 32 NO!
27c4002 dip 40 YES
27c4100 dip 40 YES
Click to expand...
I programmed a 27c4002 with the PDP-R P1 and replaced the S1 chip as well and I got a jumbled, mostly pink screen. I programmed another 27c4002 and got the same result. I thought that maybe one of the PCBs was damaged so I desoldered the new chips and soldered the old P1 and S1 chips back in and it works fine. I did a verify and compare on both 27c4002 and they were ok.
 
I have a 27C400 as P1, although my board is a PROG 4096.
 
neofan said:
I programmed a 27c4002 with the PDP-R P1 and replaced the S1 chip as well and I got a jumbled, mostly pink screen. I programmed another 27c4002 and got the same result. I thought that maybe one of the PCBs was damaged so I desoldered the new chips and soldered the old P1 and S1 chips back in and it works fine. I did a verify and compare on both 27c4002 and they were ok.
Click to expand...
P1 problem = no game boot, only this screen
What you mean with "mostly pink screen" ?
Take a pic,
What you use for S1 ? its not a 27c1001 but 1000

1738508023064-png.181393
 

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27c4100 is compatible for P slot

1738508919128.png


Dude, 27c4002 is suitable for EP rom not P-Slot

1738508923255.png


1738508927957.png
 
pierpa86 said:
P1 problem = no game boot, only this screen
What you mean with "mostly pink screen" ?
Take a pic,
What you use for S1 ? its not a 27c1001 but 1000

1738508023064-png.181393
Click to expand...
I used a 1000 for for S1. I'll have to order a 27c4100 as I don't have any on hand and the 42g-1 doesn't have an EP slot.
 
if you have a 27c800 you can try to double p1 inside or put on GND last address pin.
 
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