Blazing Star - no sound

[ne7]

Scored a no sound/for repair cart of Blazing Star a month or so back and just got a mo to start poking round to try and fix it... I've read all the usual suspect roms and the only 2 that have come up bad are the V's (as expected) both came up bad on reading when compared to mame sets...

I've de-soldered and popped in some fresh replacements but the problem remains (ranging from no sound to pops and squeeks) oddly the carts Neogeo logo jingle works...

Could this be a case of a fried PCM chip on the BK1 board? I've given the chip a little reflow just in case the pins are floating but had no success so far... Only other thing it might be is the LS139..?

Any ideas peeps?

 

[aha2940]

Have you checked the M1 chip? I had an Aerofighters 3 cart with no sound and replacing the M1 fixed it.

Regards.

 

[ne7]

Yeah gave that a read and it came back fine when compared to the mame set. tis pretty odd

 

[BIG BEAR]

I have a game withe same problem and I'm pretty sure it's the PCM for me.... swap BK1 boards or replace your PCM
BB

 

[Xian Xi]

If the V roms are good, M1 rom is good and connections are good then it's either the 74139 or the PCM but usually if it's the PCM you would still hear something but just really weird sounding. Could also be a bad P rom.

 

[aha2940]

If the V roms are good, M1 rom is good and connections are good then it's either the 74139 or the PCM but usually if it's the PCM you would still hear something but just really weird sounding. Could also be a bad P rom.

P rom is the easiest to check, just do a checksum using the UniBIOS. if it comes as OK, then the P rom is OK.

Regards.

 

[ne7]

Ah yep those P roms checked out - deffo the PCM will see if I can find a bootleg in the stacks that used original boards to repair it *fingers crossed*

Thanks for the help lads \o_