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MVS random/missing audios issue

gamezer0

gamezer0

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Hello!

I have this MV1F board that has recently started to behave weirdly when it comes to playing audio. A lot of the time, especially in games like Metal Slug X, it plays the wrong SFX when doing certain actions (play the video to hear the prisoners say "Mission 2 Start" when you save them 8|), other times it just doesn't play the level music.

I've tried several carts (which worked great on the same board in the past) and the issue persists in all of them.

Here's a video showing the issue.

Thanks in advance!
 
Hi

Did all the caps have already been replaced ?
If not, it must be done first

best,
 
Those MV1F have a rechageable battery that is prone to leak sooner than later... In that case, all the nearby components could be damaged. It's placed next to the digital audio section.

I had a MV1F with battety leaking and damaging traces and components, giving the famous Z80 error. From then, I removed it from all my other MV1F.
 
Sorry I haven't updated my progress in a while!

Thanks for the ideas. I tried cleaning it, but that didn't work. I then found (as Nebula suggested yesterday) that the battery leaked. I've already replaced it with a CR 2032 battery holder (+ the battery itself, and removed some resistance that needs to be removed when you don't use a rechargeable battery) and cleaned the area near it. When I tried turning it on... I got an even worse issue :( I got a "Z80 error". I guess I've somehow damaged some other component or connection.

I've been trying to find some continuity issues nearby and found a couple connections that might be wrong and was considering to make a little "bridge"by soldering a cable to check whether it's that or not... but I'm not fluent with electronics (not even sure I'm checking continuity right) and I'm not sure I'm doing it right, so I might just take it to some technician to repair.
 
Try jumping the connections you think are broken and see if it helps.
 
I’ve done some progress… but with strange results…

I tried bridging the 2 tracks closest to the old leaking battery. The first one (purple cable) seemed to fix the Z80 error and some of the random sounds (Metal Slug X prisoners now do say “thank you!”), however there are still plenty of random sounds.

I tried soldering another bridge (red cable) but that caused the board to constantly reset itself during powerup, so I undid it. I’m not sure whether I didn’t solder to the right place (as I can’t fully follow the track as it goes under the BR6116 chip) or I did solder it to more than one leg (they’re too tiny for my soldering skills)

Any ideas? Are there any schematics of how the tracks look like under the chips so I can more easily know where they go to?

PS: there was also some leak under the capacitor at the left of the battery. Is it possible it also got damaged? Could it be causing this sort of issue?
 

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I just realised many years ago I got a logic probe that I never used. I can't even remember how it works, but if there's anything worth trying with it that might give us some clues, let me know.
 
We managed to fix it!

I took it to a friend that works repairing and customising game consoles, and he spotted the issue straight away. As I suspected (but couldn't identify exactly which and how to fix) there were a couple broken tracks caused by the battery leak. He did a proper soldering job, et voilà, got it working 100% perfect :)

Here's a couple pics of the fix.

@DeWitt hope this leads you to some fix too! Good luck!
 

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wow, this is really cool!

thank you for this information! i fixed a couple traces, but i couldn't find the one that leads to this problem. it is good to know that it's a trace, i will have a look! sadly i dont have that much time currently. this will change in winter :-)

i wish you a lot of fun with your board :-)
 
The battery... always with the battery. Guess this is a reminder it's the first place to check on any system with a battery.
 
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