I have a DVP-CX777ES which plays CD, not DVD. DVD auto adjustment in the service menu fails. I have the service manual for this DVD changer already. The optical pickup block (DVD & CD laser) and flat cable are fine, because when I swapped the motherboard, all discs play correctly and the auto adjustment procedure works for all discs. So it is something on the mainboard, which I would like to repair. Either passive components (resistors/capacitors), RF amplifier(IC201, SP3726A) or the IC301 Servo DSP (CXD9703R). Is there anyone on this board with experience repairing Sony DVD players? Which one of these is most likely to be the culprit? Thanks for any insights.