Soundmachine right from hell

Warning! Repair this sound machine could drive you crazy. That’s a label Philips should have put at the rear side.

Everything was working on Sander’s CD555 when I powered it up for another test. And goes what… the CD-Player was not working anymore. The LCD display lighted up as on Christmas Eve and was not reacting on any keys. 

This issue looked like a problem from the power supply and it took me hours to find a SMD transistor at the rear side that caused a cold joint. When reassembling the machine the CPU of the tape deck ws not able to recognise the content of the record switch.

The real problem with this machine is, when you disassemble it and assembly it again you will get a lot of cold joints or loose contacts. It is a huge challenge and absolutely time consuming to identify all the issues. I finally ended up re-crimping the cassette connector since the record switch of the A-side was not recognised anymore. In addition the resistor 3506 was broken and the CPU did not get the information if the mechanism switched between record or play mode.

Some wires of the PCB might get loose so they need to be bridged which I basically did. At the end the machine is now playing again and I fixed two other issues I noticed a little bit late:

  • The stereo LED was not working and
  • the photo transistor of the tape mechanism did not recognised the transparent part of the tape
For the stereo LED I replaced the TEA5580 since the LED driver was not working anymore. This might happened when someone broke the PCB. The related wire got broken and when they fixed it it might caused a shortcut somehow. Who knows – it’s working now.
 
For the photo transistor I usually replace the LED with a brighter type and somehow I mixed up the LED when I replaced it and was using not my usual bright LED. Replacing it with the right type did the job.
 
Sander want me to add a Bluetooth module which is the next job. The module got ordered and now let’s wait to finish the bastard. In the meantime I continue with more tests. Hope it will now last for longer….

 

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