Got this board from a forum member, but discovered it seems to have some sound problems.
I tried replacing EPROM #5 (I assume to be the Z80 sound code) but no change.
Does anyone have any idea what could be wrong with the board? Faulty Z80 chip?
Here's a youtube of the problem:
http://www.youtube.com/watch?v=jYb6mi8hrQQ
Sound starts off fine until I beat the 1st level boss (novice course),
then it becomes glitchy like in the video.
Raiden DX PCB - Glitchy Sound - Repair help?
Re: Raiden DX PCB - Glitchy Sound - Repair help?
Would need diagnosing, but should be fixable. 
Very much doubt that it's the Z80. Got a pic of the board? I'm curious which revision it is.
Very much doubt that it's the Z80. Got a pic of the board? I'm curious which revision it is.
Formerly known here as R-Typer
Arcade game board repairer (known as 'Irongiant' and 'Vectorglow' on other arcade forums)
Arcade game board repairer (known as 'Irongiant' and 'Vectorglow' on other arcade forums)
Re: Raiden DX PCB - Glitchy Sound - Repair help?
It's the old 1993 revision, the one based on the Raiden II hardware.
Thinking maybe there was a bad joint, I tried to resolder the leads on the OKI M6295s (the ADPCM chips)
and the problem got worse, now there's a lot of noise and static and sometimes the coin doesn't even get accepted.
The problem like in the youtube clip up there was before I even messed with the board, though.
The other possible components I can think of are the ADPCM ROM (I think this is OK because the samples
sound fine when they do play), EPROM6 (ADPCM sound code?), and the YM2151 chip (I think this is OK because the FM synth sounds ok).
I'm going to try to get some replacement M6295s to replace the ones on the board.
Thinking maybe there was a bad joint, I tried to resolder the leads on the OKI M6295s (the ADPCM chips)
and the problem got worse, now there's a lot of noise and static and sometimes the coin doesn't even get accepted.
The problem like in the youtube clip up there was before I even messed with the board, though.
The other possible components I can think of are the ADPCM ROM (I think this is OK because the samples
sound fine when they do play), EPROM6 (ADPCM sound code?), and the YM2151 chip (I think this is OK because the FM synth sounds ok).
I'm going to try to get some replacement M6295s to replace the ones on the board.