MV2F - No sound on slot 1, graphics issues on both slots

[touche112]

I have an MV2F that has a few issues. On both slots, I have graphic issues:



And on slot 1, I have no sound.

Diag BIOS shows no faults, so ok there. When using a CHA board with a diag M1 ROM, it shows I have a Z80 comm issue. I've checked and confirmed all traces listed on smkdan's website - D0, C0, and Z80 lines are all ok. No issues there.

I can't find any issues over on the 257s - there was two bad traces that I repaired, and other than that, everything is checking out ok continuity wise.

Any suggestions on where to look next? Is it possible the Z80 is dead?

 

[touche112]

 

[ack]

If the sound issue is only happening with slot 1, I would check continuity between the NEO-257 to the right of the cart slots and the pins on slot 1 for sound data. Then also check the sound address lines on the slot, which I think you can just probe between the slots to make sure they are ok.

For the graphs issue. I would start by checking between the 2x NEO-257s on the left of the slots and the NEO-ZMC2, then from the NEO-ZMC2 (GAD0-3, GBD0-3) to NEO-B1.

 

[touche112]

If the sound issue is only happening with slot 1, I would check continuity between the NEO-257 to the right of the cart slots and the pins on slot 1 for sound data. Then also check the sound address lines on the slot, which I think you can just probe between the slots to make sure they are ok.

For the graphs issue. I would start by checking between the 2x NEO-257s on the left of the slots and the NEO-ZMC2, then from the NEO-ZMC2 (GAD0-3, GBD0-3) to NEO-B1.

Checked all lines between the 257s and the ZMC2, and they're all good. Same with down to the B1.

As for the sound, I turned on the board today and both slots have dead sound. The two slots are linked ok, and over to the 257 on the right is also probing ok.

 

[ack]

For the sound, I would clean your carts and cart slots, then clear backup ram and retry.