Beocord 9000 Low Volume on Playback

[Glitch]

I’m working on a Beocord 9000 Type 4812 (late production Dolby-C model) that has been in storage for several decades. My efforts so far have been to repair the degradation related to the ravages of time, like replace the drive belts that turned to goo, replace the rubber parts in the tape transport, clean and lube the tape mechanism that likely caused a motor current overload and blown fuse, repair a self-inflicted short circuit that was created while doing the above work. The power supply voltages are close to specified values and the tape transport functions (PLAY, REW, FF) are working normally. I believe that I now have the tapedeck in a similar condition to what it was when I pulled it from service so long ago.

The issue that I’m currently trying to address is a very low volume on playback. When I play a tape, I see the -20dB lights flicker on the meter, but nothing ever higher. When listening through the headphone output I can hear faint, garbled music when the headphone volume is set to maximum. Left and right channels are at a similar level. I successfully verified my tapes on another tapedeck since they are of a similar vintage to the BC9000.

I don’t have much experience with servicing tapedecks. I would like to hear some tips on how to proceed from the experts here. Hearing about common failure points or possible pitfalls would be very much appreciated.

So far I’ve been pulling and testing capacitors, trying to monitor signals on an oscilloscope, and studying the schematics.

Thank you,

Glitch

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