I have a project NBAFB which had no sound and a bad original board. I sent it to coinop cauldron and Clive advise to just buy a replacement since the orginal had been butchered.
The game was also missing the small speaker on the right side of the panel which i got from Marco and reinstalled. All 4 speaker test at 4 Ohms.
I also changed the ribbon cable for good measure.

I put the new Rottendog board in and I was still faced with the Sound board interface error on teh first boot... Looking at the board I noticed F501 and 502 had blown... After reading on it, i disconnected the speaker plug from the board and put new fuses (2.5A from original spec though the one in Rottendog were 1/2A?).

The fuses blew again anyway...

J606 power from PDB test correct (5/12v DC) but i am not getting all the readings at J605 from the transfer (2 out of the 3 18V AC read but not the 3rd one, the 80V AC reads at 88 but the 100V AC does not).
Seems like F501 and F502 get fed from the 2 good 18V AC anyway... I tested the large diode on the board and they seem to test good as well...

Anything else I am missing before i conclude I got a bad new board out of the box?

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I had not try that yet since the DMD has been working flawlessly but I can try as well. 2 fuses at a time is rough!

Clive said someone tried to replace the surface mounted IC and it was beyond repair.

the HW TP test well, -112v, -100v and 69v. I couldn't find the schematics either, their website has a schematics section which doesn't load...

Tracing the F501 fuse physically it looks like:

J605-10/11 -> J501 -> D19/22 -> C36/37 and U5/U6 and so on until the speaker out on J505 and J504.

I really wish i had another WPC95 around to try swapping things around...

In principle, I do still get the same error message "Sound Board Interface error" though i thought the old board issue was due to all the hacks on it. I am not sure if the fuse were also blowing nor did I try without pluggin the speakers since it looked pretty bad, i just sent it to Coinop for repair.

Unfortunately it has left the building...

I tried moe combination, the fuses always blow when J605 is plugged in (AC from transformer), even if it is the only thing plugged on the board, even with the other fuses removed. F501 or F502 always blow if in with only J605 plugged in...

I am hoping I am using the same Fuse capacity though, no information on the board or anywhere online that I can find?