Galaxy Fight sound issues

[mmsadda]

Hey guys, I'm hoping to learn some basic repair skills for these carts. I've got a decent bit of experience with pinball repair, and am comfortable soldering/desoldering anything you'd find on an MVS board shy of surface mount chips.

I've got a Galaxy Fight that plays fine, and the sound is mostly present, but is largely garbled. I've looked the boards over, and while it looks like there may've been moisture or something on the boards at one point, I don't see any corrosion or trace damage or anything like that. With that in mind, I've concluded I likely have a bad sound ROM. Does that sound right? This would be a V rom, correct?

Is there any good way to diagnose this, or should I just start shotgun replacing these ROMs? If I just need to start replacing ROMs, what EPROMs do I need? Bonus points if you can direct me to something from this list: http://www.arcadecomponents.com/memory.html?page=4

Thanks in advance!

Collin

 

[RetroTechRewind]

It's probably the M1 rom, or one of the V roms. Do You have an EPROM programmer? If so, you can pull them, and read the code on each one. Match it up with the files from mame and verify its the right code, aka crc32 checksum.

If it's not one of the roms, check for bad traces. If you need a replacement m1 rom, the chip you'll need is a m27c1001 or equivalent. As for the V roms, you'll likely need either a m27c800 or m27c160 depending On the file size. 800's are 1 meg, 160's are 2 meg.

If you need more help, feel free to PM me. Good luck!

 

[Niko]

Before you go removing ROMS and such, I'd check all the solder points for the V/M1 ROM legs, PCM, and NEO ZMC IC.

I had a SamSho2 that was giving me 'garbled" voices and all the solder looked fine. I reflowed the solder on the V ROM ground pins, and PCM IC and it fixed my problem.

I think the solder must have gotten brittle under one or some of the PCM legs, and it just wasnt visible.