Denon DP-11F - Platter always spins when unit powered on

[dmarley]

I have a Denon DP-11F turntable that I bought in the mid-80's and still use. It works but has developed a couple of 'quirks' presumably due to its age. In a nutshell, the platter spins constantly, any time the unit is powered up. This is a fully automatic turntable, so (if I am recalling correctly!) the platter is supposed to start spinning when the tonearm moves over the record, and stop when the tonearm returns to its cradle. Additionally, the tonearm does not automatically lift and return at the end of the record. The Start/Stop and Lift buttons all work fine. Seems to me like this might be a sensor that is no longer working, but....that's just a hunch, and a general one at that.

Neither of the issues are a show-stopper - I basically just use the turntable like you would a fully manual one. But I would like to return it to its original working order if possible.

Suggestions/thoughts on what the issue(s) might be? I know its not a high end turntable - there is some nostalgia attached to it, but if the cost to fix were too high I would probably opt to put that money into a new turntable.

Thanks in advance. Cheers.

 

[russc]

There is a service manual
Denon DP-11F - Manual - Fully-Automatic Microprocessor Control Turntable - Vinyl Engine

 

[Mark Tillotson]

There will probably be a microswitch to turn the motor on when the tonearm is in playing position, the oil/grease in the mechanism to operate the switch can get hard and dry with age, preventing the switch turning off. Certainly seen this with other make of TT.

 

[dmarley]

Thanks for the thoughts/suggestions. I did look at the service manual and nothing is jumping out at me as to where such a microswitch might be. But that definitely makes sense as a cause of this. I am going to try to open the unit up this weekend and see if I can find something that looks like it could be serving that function.

I'll report back if I find anything. Thanks again!

 

[davidsrsb]

Apart from the microswitch suggestion, another possible cause would be capacitors across the power switch failing short

 

[dmarley]

Thanks davidsrsb. That sounds like something that would be outside my skills to troubleshoot, but its good to know nonetheless.

I haven't had a chance to open up my unit and look for a suspect microswitch, but I will report back here once I do.