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Dreamcast Help repairing Dreamcast VA1 motherboard (sound issue)

MuhSanic

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Hello the good people of Obscure Gamers. I'm trying to restore a dead Dreamcast, and so far I managed to get it to work except one issue I can't seem to figure out. I hope someone can point me in the right direction.

At the moment the board has the following symptoms, probably related to the same issue:
1) Sound is very quiet and also distorted. Playback is so slow that it turns into noise. All music and sound effects in games and in BIOS are barely recognizable. They do play, but I think it's about 1/10th of the normal speed. Anything that is supposed to wait for sounds to finish playing is slowed down too. If I don't skip the boot sequence by pressing Start on the logo, it keeps waiting for the noise to finish playing, which takes almost a minute. Intro FMVs in games play at 1 frame per second, though skipping them works instantly.
2) Sometimes the image doesn't come up when the system is turned on. Turning it off and back on again fixes this.
3) When I replace the drive with a GDEMU, system time resets to 1950/03/27 17:08 and I'm unable to set it to anything else until I put the original drive back in. Other settings such as language and mono/stereo are fine. If I put the drive back in, the system remembers the time correctly. The GDEMU works fine on another system.
4) The Loop Checker disc fails on the following tests:
Memory AICA 1 and 2
Crosstalk AICA

I couldn't see any visible damage on the board except yellow blobs around X301 on both sides of the board, which I read is normal.

Any help is appreciated.
 

darkgunsou86

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you can try replacing the capacitors on the mainboard and psu. check if the pin legs on the ICs on the mainboard are ok and there's no oxidation. if there are, remove them and reflow the legs with solder.
 

stuntpenguin

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This is all very bizarre. How did your Dreamcast "die"?

When I replace the drive with a GDEMU, system time resets to 1950/03/27 17:08 and I'm unable to set it to anything else until I put the original drive back in
Why did you take the GD drive out? Did you have problems before this?
 

bart_simpson

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i have a spare sound ic i can send if any help
 

APE

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I'll second capacitors as the sound issue. Your GDEMU is known good? Did you test it in another Dreamcast?
 
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