I found a non working Sony CDP-7F which would not turn on, I managed to find the faulty burnt out resistor and replaced it and the unit turned on afterwards
The issue now is that if I wait for the TOC to be read, which it does successfully initially then after a few seconds the display shows a zero and when I select a track with the track selection button and press play nothing happens (the sled motor does not move and CD does not begin spinning) and it goes back to showing a zero and then will not accept any input at all.
However, I have learnt that if I press play immediately on powering it on, it will play the CD, goto next/previous track no problem at all!
I have cleaned the lense to no avail.
This is not ideal so I'd like to try get to the bottom of this if anyone can help. I have the service manual already but not sure where to start!