Denon DP-47f showing erratic behaviour

[BijanK]

I got a Denon DP-47f a while ago, which I really enjoy. Recently, however, it has been sporadically behaving erratically. For example, it suddenly stops playing and the tone arm returns to the rest. Or the ‘locate’ function only reaches a certain point on the record, but not further, and stops there...

The problems sometimes disappear and the device works properly again for a while – until they return.

Does anyone know this behaviour? Does my device (built in 1987) need new capacitors? Or is it just a question of some adjustments?

 

[Sleiven]

1. have the electrolytic capacitors replaced that will restore correct voltages and control . Necessary anyway, may solve arm problem too.
2. The arm in controlled by photoresistors CDS and LEDs., see Balle Clorin posts under Denon on Vinylengine. The CDS wear out and the arm controller looses control since it cannot sense the arm position correctly. CDS can be replaced but some confusion exist about which type to use, some say type 5516 is OK for all 3 photoresistors, but manual say 1 is different from the other 2

https://www.aliexpress.com/item/4001337942765.html

 

[Gigantic]

1. have the electrolytic capacitors replaced that will restore correct voltages and control . Necessary anyway, may solve arm problem too.
2. The arm in controlled by photoresistors CDS and LEDs., see Balle Clorin posts under Denon on Vinylengine. The CDS wear out and the arm controller looses control since it cannot sense the arm position correctly. CDS can be replaced but some confusion exist about which type to use, some say type 5516 is OK for all 3 photoresistors, but manual say 1 is different from the other 2
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https://www.aliexpress.com/item/4001337942765.html

replacing the capacitors probably won't fix the issues that he's experiencing, but the deck is somewhere in the ballpark of 40+ years old, so this should definitely be done while it's opened up. Capacitor kits are available on eBay and they're not terribly difficult to do if you're handy with a soldering iron. It took me a couple hours to replace all 40+ caps in my Denon DP-37 a couple weeks ago and I saved myself a few hundred bucks in the process. I've no experience with the photoresistors, however, so ymmv.

 

[BijanK]

Thank you! I used your hints to research the issue and will replace the CDSs soon. Not sure if I'll do the caps, too – never touch a running system –, but I'll have a look.

 

[Sleiven]

My q-damping was not doing anything , and my anntiskate and a VTF was off. But siuperficially everything worked. Replacing capacitors made both Qdamping and anti skate and VFT work perfect again. Arm works much smoother too. My CDS are still ok but a have a new set ready for when it is required .

 

[BijanK]

So, I did the photoresistor replacement last night, which went without any problems, but the issues persist: the tonearm will return to the rest spontaneously sometime during playback, either right after lifting off or sometime during play. So the CDS's do not seem to be (the only?) issue.

Guess I'll have to do a recap now, but I dread having to do any of the tedious readjustments. Well, maybe I just give it a shot.

 

[Gigantic]

So, I did the photoresistor replacement last night, which went without any problems, but the issues persist: the tonearm will return to the rest spontaneously sometime during playback, either right after lifting off or sometime during play. So the CDS's do not seem to be (the only?) issue.

Guess I'll have to do a recap now, but I dread having to do any of the tedious readjustments. Well, maybe I just give it a shot.

when I did my recap, the only readjustments I had to do were to re-level the tonearm and reset the tracking force, which I have to do if I change carts, which I do intermittently. it's not a big deal.