I have a MVS 4 slot with a sound problem: the right audio channel is silent and I don't know what to do! I have already replaced the YM2610 that was visibly damaged (originally all the audio was silent, and after changing that the audio was back in the left and center channel), the YM3016 and the LM324 but the right channel is still mute.
Do you hear the coin sound on both channels? (Coin sound effect comes from YM2610 directly, through it's AY-3-8910 compatible PSG/SSG output pin. It's mixed to both stereo channels at the same output level).
If you fail to hear the coin sound on the faulty channel it's a problem with the amplifier or the volume potentiometer. If you don't hear FM and PCM sounds but do hear the coin sound, then the amplifier is ok but YM3016 or analog components related to it are bad.
I tested the sound and the coin tune too is missing in the right channel. what should I check now? i guess that the potentiometer is the black volume slider (but I might be wrong), but i don't know what chip the amplifier is. Sorry for the very "step by step" approach but I'm new to the hobby and my knowledge about electronic is very limited
P.S. I forgot to say it, but I changed all the capacitors of the top and bottom board, so it shoul not be a capacitor problem!
If you board has two volume sliders, it has a headphones output. Rig a cable there and check if the headphones output has the two channels. If it does, then the power amplifier has one of it's outputs blown and need to be replaced. At least it's a fairly common audio power amplifier IC (HA13001) from Hitachi.
I tried to connect different headphones in both headphones outputs and adjust the sliders, but no sound at all comes out from them! Another symptom of a bad amplifier IC or something more?
The headphone header has sound signal at the edge pins and ground on the middle pins.
1- Channel
2- Ground
3- Ground
4- Channel
I am unsure which is Left or Right. One of the headers is the power amplifier output and the other is the headphones output. Each is affected by one of the volume sliders.
I replaced the HA13001 but nothing changed. Oh and the headphone output works, but only with a pair of old earbuds that is probably mono, since i can't tell if the right channel is there or not.
If the headphones output has sound on both pins 1 and 4, the Sound generator (YM2610 + YM3016) is fine. You will have to trace the analog part related to the HA-13001.
I only tested sound in the headphone sockets on the board, how can i test if sound come from pin 1 and 4? (i think you are speaking of connector J3 in between of the headphones connector J4 and the Headphones volume slider, right?) I need to use the multimeter? After the test what analog part do you think I should check first?
P.S. sorry I replied so late! Happy holidays by the way!
