Neo Geo MV1FZ garbage screen but no click of death

[skylab]

Hi guys. I have a mvf1z board and I consolized it. I used it with a 161 in 1 cartridge. It worked very well for a few days but today I turn on the board and not works. I get this garbage (with and without cart):

No audio and no click of death. I get the same pattern with unibios 4.0, original bios and diagnostics bios. Without bios there is the click of death (obviously). 5V is ok.
I checked data bus and address bus signals on cpu and ram with a logic probe, most of the address and data signals pulse but some signals don't pulse but stuck high or low. The CE and OE signals on the ram seem ok.
There are no broken traces between the RAM and the CPU buses. I replaced workind and backup ram but nothing has changed.
The board is in very very good condition, there are no traces of corrosion anywhere and the solder mask is perfect (compared to other mvs boards in my possession).
I also checked data and address buses of L0 and SFIX roms and all signals pulse. Palette ram and video ram don't have floating pin and all signals pulse.
But I don't know if a bad video/palette ram or L0/SFIX rom can cause this problem.
What can I do or check? Thanks.

 

[hatmoose]

If you haven't already; I strongly suggest you check out this awesome re-imagining and expansion of the NeoGeo diagnostics bios.
https://github.com/jwestfall69/neogeo-diag-bios

Its absolutely a game changer for finding and fixing these kinds of faults

 

[skylab]

If you haven't already; I strongly suggest you check out this awesome re-imagining and expansion of the NeoGeo diagnostics bios.
https://github.com/jwestfall69/neogeo-diag-bios

Its absolutely a game changer for finding and fixing these kinds of faults

I'll try but I don't think it will change anything, I've already tried with diagnostics bios 0.19 and I always get the same result

 

[StormyNormy]

@skylab is the garbage pattern static or does it change?

Does the test/service button get you into the menu?

 

[skylab]

@StormyNormy test/service buttons and dip switches do nothing with original bios and unibios. They are not used in the diagnostics bios.

 

[StormyNormy]

I have the same/similar issue with all my MV1FZs. Garbage screen looks slightly different, but is static.
They were all working fine. Stored them a while ago and now they all have the same behaviour.
Battery has been removed and thus can not have damaged any traces. I suspect it is the crystal or one of the chips (B?) from what I have been reading but can't do any in-depth testing.

Did you use the diagnostic bios already @skylab? Would be interested in the results.

 

[skylab]

@StormyNormy I used diagnostics bios 0.19 and unibios 4.0 with same results. I repaired other mvs with working/backup/video ram problems or other chip like maskrom L0 but the diagnostic bios always started.