Recent content by Retro Mecano

I would recommend to use a diag bios along with a sound test cartridge, that would be more helpful as it will point exactly which data bus is failing. I had a case similar to yours with an mv1fz, where i replaced 2 time 6116 ram and y3016 with few weeks between. These chips are very old and...

Then for the first board, I join the guys up on the Neo-ZMC2 possibility. If you have a multimeter, you might also check connection to the catridge slot connections to the zmc area. I have seen similar issue on 1 slots having this problem due to some vut traces to the cart slot. Another less...

Wierd thing is that he stated that original bios is still watchdogging.. Diag bios passes, unibios passes but with graph and sound issues. I am not sure but my finger points towards neo-do or neo-c1... Of course assuming that original bios ic is fine and socket is also fine with all...

You can press ABCD to open a menu wich does separate tests by category. Try that to check the behaviour and might see specific odd one. An additional cart coud be used to test specifically sound ICs but it seems you don't need it here as you already lentionned the game works fine with Unibios.

I had once a slot with the same behaviour with diag bios, quickly showing watchdog and reseting, drove me crazy. Found out later that some pins on the bios slot were "enlarged" and made poor contact with the bios chip. Figured that out while diag bios is running and started pressing slightly...

Already did that, and reflowed most of custom, memory ICs on the board. Checked for cut traces.. nothing changed. It's a bit difficult because i don't have the schematics behind, like MVS slots. That would make the jib somehow easier.

I just did that, sadly with no change in behaviour..

I was checking on it, and it seems my GQ4x4 programmer does not support them to read or write. It seems it does not do any Gals or Pals. Great.. Any alternative? To be honest i start to have many issues with this GQ4x4 even bur’îg regular eproms, and i am wondering what wpuld be the best...

Hello, Not familiar with these special games (got o ly to repair few MVSs), i got this PS5 Psycko arcade PCB with below issue. It's booting to a garbeled video with same pattern rapidly deflecting over the screen. No sound behind,i doubt the game is actually booting. Any idea where to start...

Well, Seems @ack was right when he said that we are learning that Mv1A's are shitty in the previous repairs. And it seems i am kind of sick to continue touching the turd.. Long story short, grabbed another faulty MV1AX, with graphich, sound, and random errors. Leasson's learned, swapper...

Did you try swapping the LS32? I got errors randomly popping up, and now it's fixed on 001100 after swapping it. Also i got misslead due to z80 RAM not well inserted in the socket. I know it's not a very clever way to solve the issue but we struggle the same sh**. At least one of us might...

Dude i respect your patience. I swear it will be the last MV1A variant i repair.. I can't even handle the repair logic since errors now make absolutly no sense after each fix. I repair 1 error, 2 other pop up. I repair a second one, the first error pop up again... Almost swapped every damn IC...

Any thoughts on the GQ4x4 programmer? I am getting some random trouble burning some eprom, started after a year with 160s, and now almost every 27c010 variants fails at 9%. Already recapped, cleaned the pins etc..

Hello good fellas, Out of despair, i am searching for some expert on CRT/PVM monitors to reach out on a live call and share the issue that i am having. I am really fed up posting threads and requesting groups/forums help without getting any feedback actually. I am struggeling since few years...

Jumping in as i follow the same repair path as @kissedin , changed also Buf at GA9, and comm error disqppered for the first try, test passed. But now rebooting give me a new one.. And efter a while, background becomes red..