Tunrtabel Denon DP-60L speed run away

[Cambiman]

Does someone got a service manual in PDF for my DP-60L ??
Cause it run's overspeed,if i start it.
If i play with the mainpower-swich on and off..10 times intermitend. it runs good few times,but a little bit slow.
For me it looks like an electronic part must be nacked
...specialy the capacitors..!??
antonius@go4more.de

[EdAInWestOC]

It seems like I written about this a hundred times recently...OK I'll make it 101 times.

Be careful with that turntable. I believe that the speed is controlled by a Denon proprietary microprocessor (I have a DP-62L and what I'm writing is based on my knowledge of that table). If the electrolytic capacitors are shot you should avoid powering on the table. The compromised electrolytic capacitors could cause the microprocessor to burn out. If that happens you have a no win situation. There are no replacements for the Denon microprocessor.

The other thing that could cause the table to exibit the symptoms you mentioned is the encoded information under the edge of the platter may be compromised. It looks like a brown gunk on the inside edge of the platter. In reality its magnetically recorded information to serve as feedback to the servo controlled circuitry. A replacement platter is also hard to come by.

When you remove the platter you will notice what looks like a tape head mounted underneath the platter. It sits very close to the inside edge of the platter. There are two tracks recorded on the edge of the platter. One is for 33RPM feedback and the other is for 45RPM feedback.

The output of that tape head is fed directly into the Denon microprocessor. A quartz crystal is connected to the microprocessor and the rest of the oscillator circuitry, frequerncy dividers and voltage/frequency circuitry is all located within the Denon microprocessor.

If the DP-60L is similiar to the DP-62L the output of the microprocessor is optically coupled to the power transistors that drive the platter motor. Be carefull when you are working on the turntable. If you try to test it with the bottom cover reomved you will end up with strange results.

Ed