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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi all,
Started this thread a while back but I think it's been archived. I have a 4002 that works OK except for the fact that the tonearm doesn't drop with a record on the platter. It just moves across the platter and switches to 45rpm looking for a single and then automatically returns to the off position. Lubricated and cleaned so no problem with mechanics.
Any help appreciated.
Norman
Hello Norman
I have a Beogram 4000 which had the same fault. It turned out to be a broken connection at the sensor in the end of the tracking arm. I would think that a previous owner had been meddling!
Pull the detector lamp module out of the arm and check solder joints and continuity of the wires back to the main sliding carriage pcb.
Regards Graham
I think Graham, as he can manually cue the arm over a record, but not over an empty platter (if I am not mistaken!), this is down to the automatic lowering section, tr12 and associated components in the diagram I just looked at... of course, I might be wrong!
I last promised Norman I would look at a picture of his board and compare to mine so we can locate the components but if he has a type number I am sure Martin will come to the rescue!
Olly
Thanks for the replies guys,
Sorry, I forgot to include the type in my first mail - it's type 5511.
Yes, you are correct Olly, I am able to lower the tone arm over a record but not over an empty platter. It will lower for the purpose of balancing if I stop the arm moving as soon as I hit start but as soon as the arm gets anywhere near the spinning platter then it won't drop - what a great safety feature.
Below are some images that may help with identification and if any more are required then I'll include them.
Thanks,
Thanks for the advice Graham,
Just to maybe eliminate that possible problem I did as you suggested and removed the sensor from the tracking arm and tested the connections. There doesn't seem to be any problems with the soldered joints and there is continuity between joints with the blue and black wires - but only when tested with the positive probe on the blue and the negative on the black. There is no continuity when the probes are reversed. Also tested the same wires on the pcb with the same result. There is also a white wire that I'm assuming carries the signal from the sensor and I'm not sure how to go about testing that. But, like I said all the wires and joints look OK.
Thanks for help.
ok Norman I know you are busy atm but I thought I would let you know I got round to having a look at a board and can confirm it is near identical to the one above. TR7, is the transistor you can see in the component side picture above just above the alu heatsink, obstructing the wires. You need to check this component with a meter in diode test, apply the positive to the base then the negative lead to the emitter, and read, then do the same for the collector. In both cases you should measure approximately 0.7V Try the negative on the base and positive on the same terminals and the reading should not change. Now measure across E - C and you should measure no change on the meter. Always best to remove the transistor for best results or the very least unsolder the base...
Now looking at that heat sink again look at the top left corner. There is a small red Tantalum electrolytic capacitor. You need to check this fella but this will be a little more difficult without a dedicated capacitance meter... You can check for a short or leakage in ohms though. It should measure infinity.
Also check the diodes in this area and maybe transistor 6, just to the right of that heat sink.
Good luck and let us know how things go!