CD 300 : Bought second hand and doesn’t work

CD 300 : Bought second hand and doesn’t work , it has been re-capped , “Bram can you have a look”

First check , Red Tape ?? on the RF shielding

what happened here

 

Power supply

1 TDA1540 under the contact spray

Laser power safety switch. with Capicitor ???

Audio Connector

 

The LM 337 is getting very very Hot

 

 

Testing only the power supply , -7volt is there , but the -18 volt is missing. there are shorts to ground between -7 and GND -18 and GND ;-(

Disconnecting this connector resolve the shorts on the power supply

The short circuits are on the Audio board.

Found the 1st one solderbridge

 

 

And the 2nd one

 

After removing  the shorts,  a quick test -18 is still missing but this is only needed for audio . Laser is working,  focus found and disc is spinning, HF is there, but the player is  not reading the Table Off Content

 

And number 3 !

 

 

Removed solderbridge number 3 and we have a nice RF signal

T.O.C. is read

Repaired -18 rail, faulty diode in powersupply. There  is audio 🙂

Replaced IC-sockets SoPhi Board

Early Sophi board, some extra wies

Oeps , almost a short

 

 

 

Ready for a test run