I have problem with Sony CDP-501, and I couldn't figure out what it could be. Tray comes out, CD in and close, I can hear laser trying to focus and then tray comes out again. I have schematic and only discrepancy I could find was -0.29V on pin 1 of IC401 (FE), instead of 2.9V, but have no idea what could have caused it ( I did substitute it with TL072 temporally). If someone is willing to help, thank you. I belive problem is not IC204 or IC304.