Mushihimesama PCB sound problem?

fuko · Post by **fuko** » Thu Mar 06, 2008 4:43 am

I just picked up a Mushihimesama board last week and I love it. Manic on this shooter is just about gaming heaven.

Anyway, something I've found is that after about 5-7 minutes of play (by about the time I reach the boss on stage 3) the sound starts to drop. I get total silence for about 2 seconds before it returns. Drops occur randomly but on average every 10 seconds. Time of play is the issue, not the stage, as quitting the game and starting a new one from stage 1 does not solve it.

It seems to be accompanied by extreme slowdown, but not always. The later stages, especially on Manic, have a _lot_ of sprites, so not sure if that's related or if slowdown is just part of this game. Also, I pulled the board tonight after a go and noticed it got rather toasty around the large black heatsink, but that might also be unrelated

I rewired the speakers this weekend (Egret II cab), and that might be the culprit, so will try out a few other boards to rule it out. I thought I would reach out and see if anyone here has ever heard of anything similar. Thanks for any help!

fuko · Post by **fuko** » Thu Mar 06, 2008 5:21 am

I just spent a good 15 min stressing out my Ibara PCB, and though there was some slowdown (not much) the sound never dropped. Starting to suspect the Mushi board.

I'm Alec · Post by **I'm Alec** » Thu Mar 06, 2008 5:43 am

hmmm... has the board ever been worked on? Any soldering? I have a cps3 board that does the same thing every so often. The sound comes back when I touch the volume pot. The board has some jumpers soldered in, so I'm guessing its cracked solder or something. Someone else knows more about it I'm sure.

RGC · Post by **RGC** » Thu Mar 06, 2008 8:07 am

Sorry to hear about this, fuko. I didn't notice any problems for the short period I owned this board. It's worth asking Dennis, the guy I bought it from, if he experienced any sound related issues. Was everything in good condition when it arrived? I certainly didn't perform any soldering on Mushi, and it was incredibly well looked after for the two weeks I had it (being my first expensive PCB purchase). Hope you can get to the bottom of this.

fuko · Post by **fuko** » Thu Mar 06, 2008 4:26 pm

Hey RGC, board and artwork were in great shape, thanks for the care.

I read in an older post here that the SH-3 hardware (from Mushi on) is very particular about sound arrangement. Specifically: the JAMMA standard expects an on-board amplifier to drive a pair of 8 ohm speakers with mono sound. As I mentioned above, I did some rewiring this weekend and now have the sound wires going from the cabinet volume control into a channel splitter, and then into a woofer/amplifier, before going on up to the top left/right speakers (both new). Might be possible this setup is causing problems, but the only way to be sure is to remove the splitter/amp/woofer from the line and retest, so I'll do that next.

fuko · Post by **fuko** » Fri Mar 07, 2008 6:58 am

Some amazing news, I think. I rewired the subwoofer/amp connection, and now haven't seen the sound drop once. I think this may have been caused by a bad or possibly unnecessary component in the line, which introduced excess resistance and the board was overheating. Hard to say, and I am not an expert. Either way I am obviously relieved as I absolutely love this game. Have had the PS2 version for a while, and it just doesn't do it justice.

RGC · Post by **RGC** » Fri Mar 07, 2008 8:37 am

Excellent.

bitkid · Post by **bitkid** » Tue Mar 25, 2008 6:17 am

Yeah that could definitely do it. If its got an audio amp on the board and that amp expects a certain ohm rather on the output side, if you are not providing enough resistance it could likely overheat. When you were having the problems was the sound distorted at all?