Garbled music tracks in gameplay and jukebox?

avramce

Kabuki Klasher
Joined
Sep 24, 2019
Posts
125
I have a problematic Twinkle Star Sprites boot that I've been trying to repair, everything in the cart works fine in gameplay, but the background music is constantly crackling and scratching. This is the only cart that I've experienced the problem with the music track, so I pulled both the M1 and V-Roms to compare them to dumps.

In this case, but the ROMs are pretty finnicky to get a read on my GQ-4x4, but when I'm able to get a proper read, the program on the ROM is identical to the dumps I found online.

From my understanding, the V-Roms are for sound effects, and the M-Roms are for music, right? The start-up chime for the game sounds clear, but it is just the music that is messed up. At this point, I've tried another M1 (using a M27C1001, same I used for Neodiag), same problem. I wonder if something is wrong with the CHA256B, but it if was, the sound wouldn't work at all.

Any help would be appreciated. I know it's a boot, but seeing it is the only game I'm interested in that isn't on the 161, I'd like to repair it if possible :P
 

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
The problem is most likely with one of the vroms or the PCM on the PROG pcb
BB
 

avramce

Kabuki Klasher
Joined
Sep 24, 2019
Posts
125
Thanks Big Bear, I was focused on the M1 since someone previously mentioned the music tracks are there. So if the start-up chime comes through clear, I can write off the M1 as working, right?
 

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
If you get sound, you're m1 is fine and it reads like that's the case.
I also forgot to mention that your jumpers must be set correctly on your PROG pcb.what are you using,a progbk1?
BB

Thanks Big Bear, I was focused on the M1 since someone previously mentioned the music tracks are there. So if the start-up chime comes through clear, I can write off the M1 as working, right?
 

Misos

New Challenger
Joined
Aug 17, 2018
Posts
57
Speaking of V-rom, is it possible to know which one is faulty before taking it off of the pcb?
For example I have a game that has a bad Intro music and I know the code in the Neobios jukebox, 0x0745, and the game has 4 v-roms, is it possible to know in which v-rom the music is stored?
 
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