Denon turntable - a cry for help

[audiogymp]

Hi AK

I have a Denon DP 2000 Quartz direct drive turntable that has stopped working. The following thread describes pretty much the same thing but the poster got no replies.

http://audiokarma.org/forums/index.php?threads/denon-dp-2000-start-stop-button-switch.706191/

I will give a little more detail about the issue in the hope that I might tempt someone who knows about these beasts to offer some advice. There isn't much discussion about the TTs in the series. I have followed what limited advice I could find but would appreciate it if someone could offer some assistance.

The problem developed over time. At first the TT would go through speed lags - sometimes they would end by themselves, sometimes I would flick the on-button or 33/45 selector and it appeared that this might have done something to restore operation but I'm not sure. It got worse and eventually it stopped spinning and wouldn't start at all.

I read a thread about a similar model (can't remember which). There wasn't much advice but what there was suggested that it might be fixed by cleaning the contacts on the controls. I did this. At first nothing. Then it started working again. I assumed that the problem was the contacts. The TT played well for a couple of months and then speed lags, stopping for a while (while I tried to work the controls) and then it stopped altogether.

A repeat of the cleaning of the controls made no difference.

I opened it up recently with a view to recapping (in case this might fix it). This thing has a lot of caps and there's no way for someone with my level of understanding to know where to start.

I tested all the switches (a main power switch and two microswitches for the on-button (for rotation) and the 33/45 selector) with a multimeter and they appeared to be working correctly.

The main power switch appears to do what you expect - the strobe comes on/goes off appropriately. However, the on-button doesn't start the platter spinning. Interestingly, toggling it seems to activate the break (pressing the on button changes the state of the platter from spinning freely to being stopped by electrical breaking applied through the motor - this is normal when you stop it spinning). That is the limit of function.

I have a copy of the service manual but it is too big to upload.

Any thoughts on what to do would be appreciated.

Thanks, Jon

 

[Elrick]

I have a DP62L, which may have similar button functions. The ON/OFF button button does not start the rotation, just powers it up illuminating the OFF button, then to start rotation, press either the 33 or the 45 button. Don't know it that helps you any, but I hope so. A decent ESR meter may be of service to evaluate the numerous electrolytic caps on the circuit board (s). ESR can usually be measured in circuit, meaning you do not have to remove the cap to perform the test. Good luck, I opened mine last year and they are intimidating with all those components. I did find a large non polarized line filter cap that had become unsoldered maybe due to shipping incidents.

 

[jmchrislip]

I had my DP-62L recapped last year. Best thing I ever did. It's hard to find someone who will take the time but it's worth it.

 

[audiogymp]

I've got an ESR meter coming from China and will have a look at the caps. Hopefully it works ok in circuit.

 

[audiogymp]

I've replaced all the electrolytic caps. The ESR meter was handy but I was getting some strange measurements in-circuit, so I decided to just swap out all the electrolytics. One 250V cap was cactus and a lot of them were 20% out, but otherwise nothing serious.

Power supply caps tested fine, so I left them alone.

After recap, the deck still doesn't work. That said, first couple of tests - nothing. Then it came back for a few stop/starts. Then nothing again. This I put down to the problem starting off as intermittent and becoming more permanent. At the time I thought the electric gods must have been having some fun but it might be enough to tell me that the ICs weren't toasted by the cap failure.

From here it starts looking a bit shotgun. Some of the transistors are gates, so they might be the problem.

If anyone has any suggestions for a more targeted approach, please say. Thanks.

 

[thebisch]

I have a DP-2000, that when I got it, speed was up and down continuously every second or so. Could not listen to a record it was so bad. I fixed it by cleaning the two speed trim pots inside. I didn't see the trim pots mentioned, so I figured I'd throw it out there.