Duo music/cd volume

[8bitplus]

Hello. I'm trying to fix a black PC engine duo. The sound is working correctly for the HU card games, but very faint for the CD background music.

I have done a complete re-cap, and initially everything worked. Then the next day NO SOUND at all.
After days of poking around I fixed a couple of traces and replaced the 2 op-amps under the board, and the one at the AV jack.

I reassembled and found the CD volume is very low on both the AV and headphone jack.

Can someone tell me which caps and amps are for the CD drive?
Thanks

[8bitplus]

After more reading it sounds like the problem may be related to the M51131L. I have a second fully working Duo and its getting 5v to pin 8 of the M51131L when playing CD music, but this Duo is getting less than 1v.
I'll take the board out of the case again and inspect that area closely...

[8bitplus]

Fixed.
Turned out the OP-Amp at IC521 wasn't getting correct voltage. I linked it to a 5v line on pin3 and the cd music is nice and high again.

[SonicBlastMan]

Sorry to necro but I had this EXACT problem and there was a hairline break in a trace going to pin 3 of IC521, also voltage drop on the same pin

I never would have found that without this thread, a million thanks 8bitplus!!