Denon DP-45F Platter Not Turning

deeply dp
Post Reply
biomayhem
junior member
junior member
United States of America
Posts: 10
Joined: 16 Sep 2017 17:50

Denon DP-45F Platter Not Turning

Post by biomayhem » 25 Oct 2017 05:48

Hi everyone,

I am new to the vinyl scene and finally decided to take the plunge by purchasing a Denon DP-45F off ebay. The buyer stated that the table was working so I bid and won the auction. However, once the turntable arrived and I set it up according to the instruction manual available here (with the counter weight properly set and the Q damping and tracking force set according to the cartridge on the tonearm), I placed a record on it, turn it on and hit play. The Quartz Lock light flashed and the tonearm moved over and lowered on the record but the platter was not turning.

So I took the record off and tried to hit play while turning the platter manually, hoping to give it a jump start but the platter still won't turn. It also makes a scratching sound when turning manually.

When I took the platter off and pressed play and the spindle does turn, it just doesn't turn with the platter on. It's as if there is too much friction since it sounds like the platter is in contact with something. Not sure exactly what to do at this point but I would like to see if I can get it to work before contacting the seller since the turntable is otherwise almost pristine. Any help is greatly appreciated. Thank you.

Spinner45
long player
long player
Posts: 2995
Joined: 01 Mar 2017 17:21

Re: Denon DP-45F Platter Not Turning

Post by Spinner45 » 25 Oct 2017 07:39

The micro-thin black magnetic coating inside the rim of the platter is likely damaged now.
It's similar to a tape recording, except that it contains a precision "recording" of magnetic pulses that a tape head underneath "reads" in order to control rotation/speed.
And the system depends on it, to operate properly.
That scraping sound is likely the tape head sensor, rubbing the coating off now.
Someone messed with this, obviously, because the tape head should never come into contact with the platter's "coating".
Oh well, it's done now.

biomayhem
junior member
junior member
United States of America
Posts: 10
Joined: 16 Sep 2017 17:50

Re: Denon DP-45F Platter Not Turning

Post by biomayhem » 25 Oct 2017 07:57

Hi Spinner45,

Thanks for your reply. I took a look at the magnetic strip on the platter and it looks to be intact. Also, when I put the platter back on, the head looks to be really close to the magnetic strip but doesn't seem to be in contact. I tried to pinpoint the location of the scraping sound and it doesn't seem to be coming from the the head, although I can't be 100% sure. Is there other possibilities? Thanks.

Spinner45
long player
long player
Posts: 2995
Joined: 01 Mar 2017 17:21

Re: Denon DP-45F Platter Not Turning

Post by Spinner45 » 25 Oct 2017 08:42

biomayhem wrote:Hi Spinner45,

Thanks for your reply. I took a look at the magnetic strip on the platter and it looks to be intact. Also, when I put the platter back on, the head looks to be really close to the magnetic strip but doesn't seem to be in contact. I tried to pinpoint the location of the scraping sound and it doesn't seem to be coming from the the head, although I can't be 100% sure. Is there other possibilities? Thanks.
Impossible to pinpoint over the internet, sorry.
You'll however get tons of speculation eventually.
The internet isn't the perfect thing everyone thinks.

biomayhem
junior member
junior member
United States of America
Posts: 10
Joined: 16 Sep 2017 17:50

Re: Denon DP-45F Platter Not Turning

Post by biomayhem » 25 Oct 2017 08:50

I do appreciate your help. And thanks for taking time to answer my questions. I guess it's just frustrating when someone claims the item is in working condition but arrived DOA. I guess I'll contact the seller tomorrow and see if I can get a refund. I guess it's best to be able to test vintage electronics before you buy.

Spinner45
long player
long player
Posts: 2995
Joined: 01 Mar 2017 17:21

Re: Denon DP-45F Platter Not Turning

Post by Spinner45 » 25 Oct 2017 17:22

Thus, the amusing name invented: E-Pray

EdAInWestOC
long player
long player
United States of America
Posts: 1356
Joined: 03 Feb 2004 01:39
Location: Glen Burine, MD USA
Contact:

Re: Denon DP-45F Platter Not Turning

Post by EdAInWestOC » 25 Oct 2017 20:22

The only way to be certain is to loosen the screws that hold the head and back it away from the platter edge. If the scraping sound goes away, you have found your culprit.

If you want to fix the issue, you can take a regular piece of copy paper and fold it over once. Cut a narrow piece from the doubled piece of paper and place the poor mans feeler gauge (folded edge down) between the servo head the the platter. You can readjust the head by moving the head back until the piece of paper can be removed from between the head and platter with both sides of the doubled paper barely touching the head and platter.

Now the platter should rotate without scraping and the turntable should work...hopefully.

One note...a Denon turntable was a very nice product but its a sophisticated piece of electronics that has a lot of electrolytic capacitors in the circuitry. These capacitors have a finite lifespan and won't last much longer than 20 years.

To make a long story short, a Denon is not a very reliable turntable unless you invest in a recap job on the circuitry.

Ed

biomayhem
junior member
junior member
United States of America
Posts: 10
Joined: 16 Sep 2017 17:50

Re: Denon DP-45F Platter Not Turning

Post by biomayhem » 25 Oct 2017 22:00

Hi Ed,

Thanks for your suggestions. I will try them as soon as I get home from work. I think I'm pretty proficient with the soldering iron so I will definitely try to recap this turn table if this problem with the platter is resolved and there are no other major problem with it. Thanks again for your help.

Joe

biomayhem
junior member
junior member
United States of America
Posts: 10
Joined: 16 Sep 2017 17:50

Re: Denon DP-45F Platter Not Turning

Post by biomayhem » 26 Oct 2017 03:24

Hi guys,

Just move the head as Ed suggested and I guess I need to get my hearing checked. Once I moved the head back the scratching sound was gone and the platter started to move. Looks like everything works now except the needle falls off the record when starting. I'll make the adjustment following the service manual. I will start looking into recapping this weekend. Hopefully I will be able to get it done in a couple of months. Thanks again guys for your help.

Joe

Post Reply