B&O 8002 turntable

[MikeBettinger]

Originally posted by MikeBettinger
I'll post the schematic, which is always a challenge. What series is your turntable? 5513, 5523, etc.?
Mike

Hi Phil,
I re-read your first post and see that you have a manual. Good.

My schematic is for the Type 5523/5526. What you need to look at is 1tr16, 1tr17, 4IC1 and 4D1. If my memory is working the slide for the encoder is broken up into different zones which, first tell the sensor arm to sense the size of the record and automatically chose 12"/10"/7" and the 33/45 speed. when the arm gets near the inner groves the pattern changes to a slow pulse if the arm is moving slowly and a faster pulse as it goes into the leadout groove. The encoder is detected by 4IC1 and the faster pulsing caused by the leadout groove charges 1C33 (1uf) until there is enough base current to turn 1TR16 on and take the base of 1TR13 to ground starting the stop sequence (mute/arm lift/return arm to rest position). Since the arm appears to be finding the record properly and based on your observation that it's 2/3rds into the record and I'm quessing not at the same place each time, most of this is functioning properly. It's a good area to start looking in.

There is also a micro switch that the encoder rail runs into at the end of it's reach that will also instigate the sequence (ES, located next to the >> switch on the schematic). It could be pinched wiring to that(since it's normally open and has to be shorted to ground to have any effect).

Hopefully this helps. Mike.