MV-1B Vertical lines graphical glitch

Hi guys,

I have an MV-1B that has these vertical graphic glitches:






It's pretty much the same as what RyuX experienced:
http://www.neo-geo.com/forums/showthread.php?275958-Bad-Luck-with-my-MV-1FZ-Mainboards&p=4327633&viewfull=1#post4327633
But the specific resolution was not pinned down by him.

I've isolated the problem to the smaller board by testing with another functional smaller board.
And I've performed continuity checks between the ZMC2 and the edge connections and they all check out.
https://wiki.neogeodev.org/index.php?title=NEO-ZMC2
https://wiki.neogeodev.org/index.php?title=MVS_cartridge_pinout

Particularly the ones bounded by the red boxes here. And also made sure they weren't shorting out against each other or GND or Vcc.


Cleaned the cart slots, the interboard connectors, basically washed it with electronic cleaner but it's the same.

Also checked the NEO-BUF bypass thingabob on the left and it too checks out.
The traces on the bottom of the ZMC2 also have continuity. And the fix layer graphics are fine so it shouldn't be anything related to the SFIX chip.

Might anyone have a clue what could be the issue? Quite stumped.

Thanks!

Guessing ZMC2?

Are they known to croak? Would be pain to swap it out.

With these boards, first thing to check are the board interconnects. Separate them then reseat. Before reseating, check the holes and pins for corrosion.

Thanks for the suggestion. The interconnect pins all look intact. It consistently fails regardless of which main board it attaches to.

I inspected it thoroughly again, and retested the ZMC2 continuity to the cartridge connector pins. At this point, I'm pretty sure it's a failed ZMC2.

Another plausible reason why that might be the case is because it was working fine then the problem appeared without any shifting about.

GadgetUK said:

Guessing ZMC2?

Click to expand...

Adding a vote for ZMC2 having dead inputs, already had some go out.

I have a broken 1B with a bad GRC2. I'd love to get it going, let me know if you give up on your repair and want to work something out