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MV2F major graphic glitch

Retro Mecano

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Hi, Starting with a watchdog on my MV2F, I managed to identify the problem by changing the NeoC1.
Now, the slot starts, but with a phenomenal glitch, in the crosshatch, in the rom diag.. I resoldered a track around the battery (the PCB is really clean, minor corrosion, minor battery leak). I also removed some ICs (zmc2, neoGo) from around the battery to clean and redo the soldering, also resoldered the Sfix Rom. But without result. Any idea which area to focus on? (Zmc2, ram, NeoIo?...) I barely managed to have a somehow readable image of the bios diag, otherwise generally it's random blocks instead of texts.
 

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The error is saying

Code:
MMIO DEAD OUTPUT

ADDRESS: 320001

1st gen: (no info)
2nd gen: NEO-C1(2) <-> NEO-F0(34)

Address 320001 is related to reading player 1 inputs and you have larger problems. I would probably start by making sure there aren't any loose pins on the NEO-C1, LSPC2-A2 and NEO-B1 chips.
 
The error is saying

Code:
MMIO DEAD OUTPUT

ADDRESS: 320001

1st gen: (no info)
2nd gen: NEO-C1(2) <-> NEO-F0(34)

Address 320001 is related to reading player 1 inputs and you have larger problems. I would probably start by making sure there aren't any loose pins on the NEO-C1, LSPC2-A2 and NEO-B1 chips.
I did reflow those 3 chips already.
One thing to note is, i took the NeoC1 chip that was in my MV1FZ slot, that was causing sound issues only, but no graphic or boot problems.

Unless pinout betwwen 1 slot and 2 slot of NeoC1 are different, and what was causing the sound problem in the 1 slot, is now causing these glitches in the 2 slot...
 
The pinout of the NEO-C1 is the same between the boards. I would definitely start by replacing it since you know its bad. It handles a lot of the output enable signals all over the board. Its possible the heat from removing/adding it caused further brokenness in it.
 
The pinout of the NEO-C1 is the same between the boards. I would definitely start by replacing it since you know its bad. It handles a lot of the output enable signals all over the board. Its possible the heat from removing/adding it caused further brokenness in it.
I managed to swap Neo-C1 with a good one, and the error changed to "WRAM Data upper". Continued swapping both Rams in D3 and D4, and now i can tell from the screen flash that the diag test passed succesfully without errors.
20250411_141928.jpg

Now the issue is the graphic is still massivly garbeled with the same exact behaviour.
With Unibios 4 i can still launch games.
20250411_141644.jpg

With stock bios it keeps watchdogging.
 
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