MVS sound issue

[Neo'nate]

Its been a very long while since Ive fired up an MVS (1 slot Mv-1a) and for some reason it will not play any sound. There is crackling coming from the sound pot and within the settings on the test menu, when I set the sound to left,right or center, some but not all times sound can be heard. trouble is the setting never saves and for some reason goes back to default setting of 'no sound'

What am I doing wrong? Or is this a hardware fault?

[geotrig]

The test menu is just that and doesnt set the sound to any side or channel ,its testing each speaker and is not saveable so you are not doing anything wrong . It sounds like a hardware fault tbh ,anything happen if you prod at the sound adjusment knob ? or the sound chip or z80 ?

[Neo'nate]

Yes there is crackling, showing me that it is responsive, maybe I'll take a closer look and give components a clean. I'll also try some alternative carts and see if the fault is cart specific? I haven't used the motherboard for ages, but it was in working condition al the while ago and its certainly not the cab. It just seemed odd that any of the settings changed on the test menu didn't save as you cycled through them. So by default, on boot within the test menu it fell on "no sound" or is this the same all the time? Honestly I used to know the hardware inside and out! I literally haven't used anything MVS for ages and cant seem to find any info on this via the wiki.

[geotrig]

I'm almost certain it defaults to "no sound" in the test menu but doubting myself now good idea to check another cart but even without a cart i think the sound test can be run so more than likely it is the mb.

[Neo'nate]

Yes understood, so the test menu doesn't impact the setting, it is just there to provide a "test" function. I think you are correct it defaults to no sound, thus giving you an option to test L/R speakers and then both together. If I continue to get nothing, it's a mobo issue for sure.

Thanks for your time and help, its clarified a few thing for me for sure. . . I was under the assumption (like with similar hardware from the time) that the settings impacted on the function, but clearly with MVS they don't.

Cheers!

[Flinnster]

It isn't doing anything like this is it?

[Neo'nate]

No its literally giving me nothing, I might leave it running for longer and see what happens as in your video. Did you find a solution?

[Flinnster]

No not yet. I got as far as working out what caps I needed to order to replace the lot of them on the MV1-FS.
Not managed to get back to the repair bench since

If you're not getting any audio at all, may be worth checking around the NEO-D0 and yamaha YM chips for corrosion, bad contacts and traces.

[Neo'nate]

Ok cheers. I'll take a look and good luck with yours!