Scott A426 playing only left channel when using phono input - HELP!!

Hi everyone, I am having a big headache in trying to figure out why my Scott A426 is playing on the left channel only when i use the phono input.

The turntable is working fine, been tested with another receiver, cables etc all is ok.

As this happens only when i select the phono input (everything works ok when using any other input), I thought it could have been an issue with the pre amp board. So far I have tested the caps and transistors on the board and all seem to be within range. All contacts seems ok, nothing look loose etc...

Any idea what should I look for next?

Thanks in advance!