When a disc was loaded, there were a few quiet clicks and then the tray opened again. As pin 1 of 7IC101 (CX20109) never went high and the clicks appeared to be coming from the focus coil a fault in the focus servo was suspected. Even after nulling the circuit using the procedure from the service manual a DC offset of over 1 volt was still present at the coil so 7IC106 and 7IC107 (both NJM4558S) were replaced and the output transistors 7TR112 (BD137) and 7TR113 (BD136) checked, all without curing the fault. As the final stage of 7IC106 is a summing amplifier the three inputs were next disconnected in turn, however the offset remained. The cause of the fault was in fact not a faulty component but the glue used to secure the wiring to the PCB, this had become slightly conductive around the feedback connections between 7IC106 and 7TR112 and 7TR113. Removing the glue restored normal operation. [Beogram CD 50]