MV1B Audio problem

pierpa86 · Mar 12, 2023

Hello guys,
Recently i have consolized an MVS1B
Before starting to solder all the connectors I tested the card and everything worked, now I have an audio problem where only the sound of the coins works.
I also used the two PCBs to convert the card to horizontal, maybe it can be a false solder that, moving the card a little, stops working.

Ryoandr · Mar 12, 2023

Coin, cursor sounds typically come from YM2610 SSG channels, which are directly output by the 2610 and mixed after the DAC. It means all the amplification is working and the fault is before.
Gotta check DAC itself, lines between DAC and 2610 (3 traces), 2610 itself. I guess the opamp between the DAC and SSG injection could also be faulty.
As for the flat mod, the cart is less secured than in original position, so it's more sensitive to bumps.

pierpa86 · Mar 12, 2023

Ryoandr said:
Coin, cursor sounds typically come from YM2610 SSG channels, which are directly output by the 2610 and mixed after the DAC. It means all the amplification is working and the fault is before.
Gotta check DAC itself, lines between DAC and 2610 (3 traces), 2610 itself. I guess the opamp between the DAC and SSG injection could also be faulty.
As for the flat mod, the cart is less secured than in original position, so it's more sensitive to bumps.

Thanks for you fast reply, after some swear word i reflow all contacts of the flat mod...... yes was that :thumbsup:

I must have left a shim when I was screwing it to close and it forced a bad contact.

pierpa86 · Mar 12, 2023

Anyway now everything works, after two days of 3d printing welding this is the result.
The card shell is a modified version of OpenMVS for MV1C :thumbup: