OK, so not quite as old as that 1970s tape recorder that we fixed last week, but a 1996-vintage Philips AZ8640 Radio-Tape-CD boombox. The CD had stopped working, but the tape and radio were still fine.
Opening up, these things are not meant to be easily disassembled. They tend to be built from the inside out, with not much thought about future disassembly or serviceability.
When we fix old electronics, there are a few “usual suspects”, which quite often give us a fix. Old electrolytic caps are one…. they dry out after a decade or two of service. Another is bad connections or solder joints.
Solder joints, cracked or so-called “dry”, can be hard to see sometimes. Wiggling the component legs can help you see them, or simply re-touching all joints with fresh solder can do the trick. This one was quite spectacular, however.
A 3-legged power transistor that supplies power to the CD mechanism, looks like it had moved on its heat sink, and the 3 solder joints had completely detached from the PCB. Re-soldering the 3 joints brought the CD back to life. The transistor looks like it’s held to the heatsink by a spring clip rather than a screw. Perhaps the spring has failed. It’s very hard to see, and it’s a nightmare to remove the circuit board to check.
Interestingly, the transistor, a BD236, is still available new from Farnell at €0.72! Here’s hoping for another 30 years of service.
