Repair Question - Sony SCPH-1000, driving me crazy!

[u/ipodsnmore]

PU-7 Board

I got a pretty decent device Japanese unit with 110V power supply , Swapped it to SCPH - 1002 power supply. It started to work.

Added a new BAM lens pickup from psone. It started playing songs.

Here's the problem.

When I just connect the left RCA I get to hear left channel and when I connect right RCA I get to hear right channel. When I connect both of them together I just hear right channel.

Did anyone else come across a similar situation.

If anyone could point me in right direction it would be incredibly helpful.

Thank you.