Denon dp-47f tonearm lift issue after recap

[Ethan Pierce]

I recently purchased a Denon DP-47F turntable and everything was functional except I noticed tracking issues. This table is supposed to be an exceptional tracker so obviously something was amiss. I turned the VR5 pot (tracking weight potentiometer) all the way and still the issue was not completely resolved. I purchased a tonearm scale and was able to overcompensate with extra anti-skate/tracking force but I realized I would rather have a long term solution.

So, I recapped the all the electrolytics Nichicons from Mouser and seemingly no mistakes were made to my knowledge, looks nice and clean. I went to test the turntable out yesterday and it seems the tonearm does not want to lift. I have been doing my research and I have three theories on what went wrong but I would like this wonderful community's opinion because I could be way off. But first let me list what works and what doesn't because it's very odd to me:

- powers on
- anti-skate/tracking force affects the weight of the arm
- platter spins at 33 and 45 when tonearm is manually moved into the platter area

- start button is non functional
- stop button is non functional
- raise tonearm button non functional
- tonearm does not auto return

Theory 1:
Because VR5 pot was still cranked when I first tested the table, the new cap caused an overload somewhere in the servo and fried maybe the IC leg or photo resistor?

Theory 2:
When turning the table upside down to work on it, some of the Tesla coiled wires in the tonearm broke or separated

Theory 3:
The 1uf 50v caps I bought do not have the positive side labeled so potentially I could have put a cap in backwards. I was very careful when installing new caps but you never know

Does anyone have any insight into which, if any, of these theories is on the right track?

 

[richardloh]

Oops .. sorry to hear as I am about to embark on recapping of my also newly acquired dp-47f and this is indeed worrysome ...

Unfortunately not technical to really help and can only hope you resolve these issues soon but will say:

#1 unlikely as it designed for presumably cap of same uf and voltage rating
#2 hope this is not the case but you may have to reopen to examine
#3 this can be quickly checked when doing #2

Will be watching this thread .. and all the best

 

[Ethan Pierce]

Oops .. sorry to hear as I am about to embark on recapping of my also newly acquired dp-47f and this is indeed worrysome ...

Unfortunately not technical to really help and can only hope you resolve these issues soon but will say:

#1 unlikely as it designed for presumably cap of same uf and voltage rating
#2 hope this is not the case but you may have to reopen to examine
#3 this can be quickly checked when doing #2

Will be watching this thread .. and all the best

Well, thank you for the reply and I have made progress. I found my main error which is me being dumb and ordering the wrong caps. I accidentally ordered Nichicon bi-polar caps, I was not aware that in the case of electrolytics, non polarized and bipolar are the same thing. Doh! It makes sense that I fried something but since the caps where all the right values, hopefully I didn't do too much damage.

I ended up putting the old caps back in and now the unit has improved some. I can start the table by choosing the speed and manually moving the arm onto the platter. The auto return works too, which is odd to me but hey, it's an improvement. Also that tells me one very important thing, that the Tesla coils inside the arm are not broken, yay! Also, the tracking force seems to be as functional as it was before, the arm does the happy dance when the unit is turned on.

So, I tested all the voltages around the unit and the voltages seem ok coming in and out IC2 which powers the arm. I tested for cold solder joints but none that I could find. I replaced the photoresistors with 5528 5506 5526 because 5516 did NOT work. So, tonight I'm going to start by checking each component going from the start button to IC2 pin 1. According to the flow chart, the lifter and repeat buttons are tied into that area as well and none of those buttons are working right now. I'm determined to fix this so I'm going to keep updating this thread in case it helps anyone else troubleshoot. It would make sense to me that because the caps were non polarized that a diode or transistor took a surge in the wrong direction when the unit was turned

 

[spark1]

Using bi-polar caps instead of polarized will not cause a problem. It is the converse that causes problems.

 

[Ethan Pierce]

Using bi-polar caps instead of polarized will not cause a problem. It is the converse that causes problems.

Interesting. That's good to know. Nothing is visiblly fried so that makes sense.

In this case that actually raises more questions as to what happened to knock out a whole section of the functionality. Seems like issue is very specific to my situation but @spark1 do you know anything about these tables?

I don't think so but I wonder if it's a matter of adjusting the VR4 voltage. That wouldnt explain why lift and repeat don't work either. Hmmm

One other symptom is that the Locate button moves the arm for a milli-second and then the arm drops again

I'll just have to start testing the individual components I guess

 

[spark1]

Interesting. That's good to know. Nothing is visiblly fried so that makes sense.

In this case that actually raises more questions as to what happened to knock out a whole section of the functionality. Seems like issue is very specific to my situation but @spark1 do you know anything about these tables?

I don't think so but I wonder if it's a matter of adjusting the VR4 voltage. That wouldnt explain why lift and repeat don't work either. Hmmm

One other symptom is that the Locate button moves the arm for a milli-second and then the arm drops again

I'll just have to start testing the individual components I guess

Sorry, I do not. Just wanted to pass on the capacitor info. Good luck!

 

[richardloh]

Hey Ethan,

Good to know that you had progressed with identified wrong polarity capacitors used and especially #2 is not the case !

Using bipolar to me will indeed causes unreversible component damage issue in my limit knowledge as you had mentioned albiet not sure if they are the 9x 1uf 50v ones since it allows current to flow in unintended opposite direction instead of controlled direction .. I may hv missed the point by Spark1.

Do continue to check for wrong polarity of all the 36 capacitors just in case will be my thinking as well as all diodes if ok besides the bridge rectifiers which should be fine if voltages are ok since it should be easy to do. Any soldering bridged of newly installed capacitors will be next ...

I would also swap out the VRs if new ones are available just in case they are damaged as it was reported that they are weak .. especially if adjustments to them yielded no effect.

I am in Singapore of far east and do let me know if you need specific ICs which I will try to find from China since not expensive stuff albiet some time needed .. and hope you know that you are not alone on this journey as I would like if I am in the same situation when I recap mine

Await your further good news

PS: spent quite a bit of time on mod preparation including on voltage 100v to 230v conversion as well as using added 12v regulation with Walt Jung's super regulator board especially for M5128 with little design margin and seems errors of cap value and IC101/201 naming was wrong .. enclosed cap marked up if it helps anyone

 

[spicer]

I recently purchased a Denon DP-47F turntable and everything was functional except I noticed tracking issues. This table is supposed to be an exceptional tracker so obviously something was amiss. I turned the VR5 pot (tracking weight potentiometer) all the way and still the issue was not completely resolved. I purchased a tonearm scale and was able to overcompensate with extra anti-skate/tracking force but I realized I would rather have a long term solution.

So, I recapped the all the electrolytics Nichicons from Mouser and seemingly no mistakes were made to my knowledge, looks nice and clean. I went to test the turntable out yesterday and it seems the tonearm does not want to lift. I have been doing my research and I have three theories on what went wrong but I would like this wonderful community's opinion because I could be way off. But first let me list what works and what doesn't because it's very odd to me:

- powers on
- anti-skate/tracking force affects the weight of the arm
- platter spins at 33 and 45 when tonearm is manually moved into the platter area

- start button is non functional
- stop button is non functional
- raise tonearm button non functional
- tonearm does not auto return

Theory 1:
Because VR5 pot was still cranked when I first tested the table, the new cap caused an overload somewhere in the servo and fried maybe the IC leg or photo resistor?

Theory 2:
When turning the table upside down to work on it, some of the Tesla coiled wires in the tonearm broke or separated

Theory 3:
The 1uf 50v caps I bought do not have the positive side labeled so potentially I could have put a cap in backwards. I was very careful when installing new caps but you never know

Does anyone have any insight into which, if any, of these theories is on the right track?

I don't know if this relates and not sure what issues you have with tracking but I have a DP 31L that had arm resistance affecting tracking. The stylus had to drag it along, enough it offset the cantilever, not much but you could see it. I disassembled the arm suspension, removed the (tiny) ball bearings, cleaned everything, reassembled dry and checked it's freedom of movement. It's been perfect every since. It was the factory lubricant that was the problem. Have no idea how common this is with tone arms but that was the case with this one.

 

[spark1]

Hey Ethan,

Good to know that you had progressed with identified wrong polarity capacitors used and especially #2 is not the case !

Using bipolar to me will indeed causes unreversible component damage issue in my limit knowledge as you had mentioned albiet not sure if they are the 9x 1uf 50v ones since it allows current to flow in unintended opposite direction instead of controlled direction .. I may hv missed the point by Spark1.

Do continue to check for wrong polarity of all the 36 capacitors just in case will be my thinking as well as all diodes if ok besides the bridge rectifiers which should be fine if voltages are ok since it should be easy to do. Any soldering bridged of newly installed capacitors will be next ...

I would also swap out the VRs if new ones are available just in case they are damaged as it was reported that they are weak .. especially if adjustments to them yielded no effect.

I am in Singapore of far east and do let me know if you need specific ICs which I will try to find from China since not expensive stuff albiet some time needed .. and hope you know that you are not alone on this journey as I would like if I am in the same situation when I recap mine

Await your further good news

PS: spent quite a bit of time on mod preparation including on voltage 100v to 230v conversion as well as using added 12v regulation with Walt Jung's super regulator board especially for M5128 with little design margin and seems errors of cap value and IC101/201 naming was wrong .. enclosed cap marked up if it helps anyone

View attachment 2931152

Again, bipolar caps are perfectly fine for replacing polarized caps, albeit more expensive.

 

[richardloh]

Again, bipolar caps are perfectly fine for replacing polarized caps, albeit more expensive.

Hey Spark1, Noted and tks but pls explain further .. as mentioned, how is unintended current flow via bipolar caps be ok and unlikely the cause of permanently damaging other part of the electric circuit ? Is it because expected dc after regulation and not ac power ?

I draw comparison with diodes but certainly can be completely off the mark.

Cheers.

 

[spark1]

This may help:

https://www.tdk.com/en/tech-mag/capacitor/03#:~:text=Because%20the%20capacitor%27s%20electrode%20plates,a%20capacitor%20blocks%20DC%20current.

This thread, while related to use in AC circuits, may help as well:

https://audiokarma.org/forums/index.php?threads/polarized-capacitors-in-crossovers.920908/

 

[Ethan Pierce]

I don't know if this relates and not sure what issues you have with tracking but I have a DP 31L that had arm resistance affecting tracking. The stylus had to drag it along, enough it offset the cantilever, not much but you could see it. I disassembled the arm suspension, removed the (tiny) ball bearings, cleaned everything, reassembled dry and checked it's freedom of movement. It's been perfect every since. It was the factory lubricant that was the problem. Have no idea how common this is with tone arms but that was the case with this one.

That is good information, I hadn't heard of that fix before. I am really trying to avoid taking the arm apart because its such a delicate piece of the puzzle. Our symptoms don't sound quite the same but its worth looking into

 

[Ethan Pierce]

Hey Ethan,

Good to know that you had progressed with identified wrong polarity capacitors used and especially #2 is not the case !

Using bipolar to me will indeed causes unreversible component damage issue in my limit knowledge as you had mentioned albiet not sure if they are the 9x 1uf 50v ones since it allows current to flow in unintended opposite direction instead of controlled direction .. I may hv missed the point by Spark1.

Do continue to check for wrong polarity of all the 36 capacitors just in case will be my thinking as well as all diodes if ok besides the bridge rectifiers which should be fine if voltages are ok since it should be easy to do. Any soldering bridged of newly installed capacitors will be next ...

I would also swap out the VRs if new ones are available just in case they are damaged as it was reported that they are weak .. especially if adjustments to them yielded no effect.

I am in Singapore of far east and do let me know if you need specific ICs which I will try to find from China since not expensive stuff albiet some time needed .. and hope you know that you are not alone on this journey as I would like if I am in the same situation when I recap mine

Await your further good news

PS: spent quite a bit of time on mod preparation including on voltage 100v to 230v conversion as well as using added 12v regulation with Walt Jung's super regulator board especially for M5128 with little design margin and seems errors of cap value and IC101/201 naming was wrong .. enclosed cap marked up if it helps anyone

View attachment 2931152

this is very helpful, thank you! I was wondering if the schematic might have had errors or changes through this models lifespan. I will take a look tonight and let you know what I find

 

[spicer]

That is good information, I hadn't heard of that fix before. I am really trying to avoid taking the arm apart because its such a delicate piece of the puzzle. Our symptoms don't sound quite the same but its worth looking into

Right, a delicate piece. With mine, not only the stylus being offset to pull the arm, when lightly balanced and on the cue pad if slightly pushed the arm would come to a stop and return a touch before coming to rest as if anti skate was quite high when it wasn't even in play, neutral. Sticky lube was the problem and disassembly with cleaning was the fix for it. When I took it apart and removed the little ball bearing they were in fact a bit sticky. I'd want to be sure before taking the arm apart, I had experience but it is a tedious bit of work and one cannot lose a little ball bearing, they are tiny.

 

[richardloh]

Hi Ethan,

Read on the below from 2 owners and not sure if it helps.

Cheers.

 

[Ethan Pierce]

Hi Ethan,

Read on the below from 2 owners and not sure if it helps.

Cheers.

View attachment 2931918View attachment 2931919View attachment 2931925

Ok cool, this answer feels like it was years in the making! Thank you for piecing this all together. If I ever get this thing working again maybe I can compile all the different info I've collected throughout the various threads into one place.

I actually do have an oscilloscope but I literally just bought it for this and future project so I don't exactly know how to use it yet. But I give the VRs a slight turn in each direction to see if there was any change in behavior. No change so far but this info will definitely come in handy once it's time calibrate.

Thank you very much for time and effort!

 

[richardloh]

Hi Ethan,

My pleasure !

I have a running Garrard 301 with sme3012R and Ortofon GM Gold classic mk2 and a NOS NIB 401 and ex owner of Michell Orbe and Gyrodec which I sold as a current audiophile also into server and streaming playback. I bought this mint dp-47f from Japan on 100v as I retired 2 yrs plus ago and this is not too expensive, mint and untried fully automatic one as a project for weeks or months to come. Not an experienced tech or diyer but having limited experiences with available temp controlled soldering station, desoldering station, portable scope etc. and had done some minor electrical/electronic mods.

Had been reading here and other for the shared experiences of generous owners/ex-owners to embarked on the following modifications:

1. Convert running 100v to local 240v typical:
- Talema encapsulated 2x12vrms 230v xformer
- Walt Jung super regulator to replace stock unregulated 12vrms .. IC M5128 operating rates input voltage is +/-15v with max +/18vpeak leaves little margin especially since 230v xformer instead of typical 240v from wall

2. Recap 36 stock ones with a combination of long life 105 deg C Panasonic FC, FM and Nichicon UPW .. avoiding 85 deg C Audio grade ones

3. Eliminate captive phono rca and powercord albiet taking hit on signal quality due to more breaks but allows me to use/try various available phono cables as well as making it look nicer to me

4. Bracing with extruded 90 deg L joints at all locations where 2 wooden pieces meets

5. Random application of damping materials on internal wooden pieces and maybe the platter

6. Lub motor and tonearm mechanism

7. Contact cleaner spray of all VRs and pots, especially the Antiskate one

Not sure how successful I will be in keeping the dp-47f running after these mods and a bit worried with all these VRs but it had been fun so far reading up to gather information and learning.

Cheers.

 

[Ethan Pierce]

Hi Ethan,

My pleasure !

I have a running Garrard 301 with sme3012R and Ortofon GM Gold classic mk2 and a NOS NIB 401 and ex owner of Michell Orbe and Gyrodec which I sold as a current audiophile also into server and streaming playback. I bought this mint dp-47f from Japan on 100v as I retired 2 yrs plus ago and this is not too expensive, mint and untried fully automatic one as a project for weeks or months to come. Not an experienced tech or diyer but having limited experiences with available temp controlled soldering station, desoldering station, portable scope etc. and had done some minor electrical/electronic mods.

Had been reading here and other for the shared experiences of generous owners/ex-owners to embarked on the following modifications:

1. Convert running 100v to local 240v typical:
- Talema encapsulated 2x12vrms 230v xformer
- Walt Jung super regulator to replace stock unregulated 12vrms .. IC M5128 operating rates input voltage is +/-15v with max +/18vpeak leaves little margin especially since 230v xformer instead of typical 240v from wall

2. Recap 36 stock ones with a combination of long life 105 deg C Panasonic FC, FM and Nichicon UPW .. avoiding 85 deg C Audio grade ones

3. Eliminate captive phono rca and powercord albiet taking hit on signal quality due to more breaks but allows me to use/try various available phono cables as well as making it look nicer to me

4. Bracing with extruded 90 deg L joints at all locations where 2 wooden pieces meets

5. Random application of damping materials on internal wooden pieces and maybe the platter

6. Lub motor and tonearm mechanism

7. Contact cleaner spray of all VRs and pots, especially the Antiskate one

Not sure how successful I will be in keeping the dp-47f running after these mods and a bit worried with all these VRs but it had been fun so far reading up to gather information and learning.

Cheers.

Damn! Where did you find a 301?! That's the dream table, actually the dream is to find one at a garage sale or something because they are on auction cites but I will never be able to afford those prices.


I saw most of those results online as well and actually got some more interesting results when I googled Denon DP-47F ICT303. But anyway, all my caps are now correct, polarized and tested well. The original caps were not far off spec. But I did find a dead resistor so I am on my way. I am going to pick up some metal resistors today and will hopefully get this thing running by the weekend.

Cheers!

 

[nbndtrain]

Here's a pic of mine which I re-capped. Double check polarities. Make sure the inside rim of the platter is perfectly clean with iso alcohol.

 

[spark1]

Damn! Where did you find a 301?! That's the dream table, actually the dream is to find one at a garage sale or something because they are on auction cites but I will never be able to afford those prices.


I saw most of those results online as well and actually got some more interesting results when I googled Denon DP-47F ICT303. But anyway, all my caps are now correct, polarized and tested well. The original caps were not far off spec. But I did find a dead resistor so I am on my way. I am going to pick up some metal resistors today and will hopefully get this thing running by the weekend.

Cheers!

Bottom line, working on the unit caused new problems. This strongly suggests either a) incorrect parts or b incorrect orientation of new parts, or c) bad soldering work (cold joints, solder bridges, etc). Have you assured that any such issues have been identified and resolved?

I see that you (apparently) removed the BP caps and replaced them with polarized. Wasted work, but as long as you got them in correctly, no problem.

Can we assume that you cleaned the stylus, and examined it under magnification for excess wear and/or damage? You might be amazed at how much crud can build up on a stylus and cause tracking/distortion issues.

What cart/stylus are you using, and at what tracking force? What is the difference between the tracking force actually being applied vs the tracking force set with the knob? From what I could glean from your initial post, his is the issue you are trying to resolve, correct?