Sensor arm lamp output is becoming marginal (filament degrades) and/or positioning with respect to the lens is "on the edge".

Martin

Thanks Martin,

Either maybe the case. It also maybe the lens is dirty after all these years. Maybe....

In any case, the 4002 is again playing records, at least for now.

Jeff

My 4002 which was working perfectly will no longer 'see' a record it just goes to the end (changing speed 1/2 way) then returns. I can clearly see the light on the sensor arm shining on the record and the B&O logo is illuminated (same bulb?)  Putting a piece of black paper under the sensor arm whilst it is trying to play will not trick it into working. As it was OK, I take it the adjustments are OK, at least nothing has moved.

No caps have been replaced in this set (yet)  Where would be the best place to start looking?? Thanks

The best thing would be to put an oscilloscope to the sensor signal path. Alternatively a DC voltmeter where shining a flashlight on the sensor (I use a dentists mirror for this) should produce a DC voltage from the sensor. The sensor is a tiny piece of glass, it breaks quite easily (I have new ones in stock if you need, not the easiest part to replace though).

Check for the usual issues; Cracked solders, bad connectors etc.

There are some tantal capacitors on the circuit board and I've noticed them starting to fail, however pointing a finger to one particular component is impossible without measuring about a bit first. Check the sensors output first.

Martin

Problem was a bad connection to the solenoid. Re-soldering seems to have cured the problem

Well the problem has returned.There seem to be 4 wires coming out of the detector arm. The manual is not clear which provide the signal. could you advise which colour wires to test between and what sort of voltage to expect. Thanks

just to bump this up, does anyone know which wires to test for an output from the detector arm?

Thanks

OK the sensor is producing an output back to the board under the deck.

I notice the manual raise/lower switch will not lower the arm either. Where do I look next?

Thanks