Turntable starting spinning backwards

snap, crackle and pop
Post Reply
Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Turntable starting spinning backwards

Post by Surfalia » 24 May 2018 07:10

My old Sony PS-X30 turntable started spinning backwards(conterclockwise) less than 12 hours after I had sprayed electric contact spray cleaner in and around all the buttons/switches. Any ideas where to begin tracking down what is the cause?

Coffee Phil
vinyl addict
vinyl addict
United States of America
Posts: 5379
Joined: 20 Sep 2008 08:22
Location: California

Re: Turntable starting spinning backwards

Post by Coffee Phil » 24 May 2018 19:00

Hi Surfalia,

Welcome to the forum.

My fear is that some of the solvent got under the platter and altered the magnetic coating which is used for the position and speed sensing for the control loop.

Look under the platter and I expect you will find magnetic oxide coating similar to that on tape. If it looks like it dissolved and ran I'm afraid you will need a new platter as I don't know if anyone will be able to replace the oxide and magnetize it with the correct pattern. Organ Donor may be your best bet. https://organdonorparts.com/

Phil



Surfalia wrote:My old Sony PS-X30 turntable started spinning backwards(conterclockwise) less than 12 hours after I had sprayed electric contact spray cleaner in and around all the buttons/switches. Any ideas where to begin tracking down what is the cause?

Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Re: Turntable starting spinning backwards

Post by Surfalia » 24 May 2018 19:09

Thank you Phil. I wanna cry now but I will take a look first :)

Coffee Phil
vinyl addict
vinyl addict
United States of America
Posts: 5379
Joined: 20 Sep 2008 08:22
Location: California

Re: Turntable starting spinning backwards

Post by Coffee Phil » 24 May 2018 22:19

Defiantly take a look. Some direct drive motors have a tendency to stare in the reverse direction. On such machines there is circuitry to detect and correct this. The fact that it happened after cleaning makes me suspect that the magnetic oxide got damaged.

Phil




Surfalia wrote:Thank you Phil. I wanna cry now but I will take a look first :)

euclid
senior member
senior member
Posts: 409
Joined: 28 Sep 2002 15:17
Location: Silver Spring, MD, USA

Re: Turntable starting spinning backwards

Post by euclid » 25 May 2018 06:28

Try spinning it forwards before applying power. If it keeps going forward and settles down to the correct speed, something in the startup logic or sensing is wacky.

jackie
senior member
senior member
Posts: 692
Joined: 17 Feb 2003 17:46

Re: Turntable starting spinning backwards

Post by jackie » 25 May 2018 16:08

Use a warm hair dryer on areas that you treated

Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Re: Turntable starting spinning backwards

Post by Surfalia » 25 May 2018 17:12

Could a start or run capacitor cause this problem?

Coffee Phil
vinyl addict
vinyl addict
United States of America
Posts: 5379
Joined: 20 Sep 2008 08:22
Location: California

Re: Turntable starting spinning backwards

Post by Coffee Phil » 25 May 2018 17:44

Hi Surfalia,

Your turntable is a direct drive. Most direct drive turntables use some form of electronically com-mutated brushless DC motors. I have seen a schematic of direct drive with a poly-phase AC motor with electronic control of resistance feeding the motor. Those motors could have a phase shift capacitor. They are not common. Sadly the service manual in not on this site. There is only the owner's manual. It is from that manual that I know your machine is a direct drive and there is a magnetic ring of some sort under the platter. Now that ring could be a ceramic magnet in which case it is unlikely that you damaged it. My fear is that is an oxide coating as on magnetic tape and some of it washed away.

Do look under the platter to see what you have. Also as the other poster suggested clean up the residue of the spray. I'm not worried over the spray remaining in the switches. If it is electronic control any lubricant which may be in it should be appropriate for switches. I'm wondering if contaminants got washed onto the circuit board.

Phil
Surfalia wrote:Could a start or run capacitor cause this problem?

Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Re: Turntable starting spinning backwards

Post by Surfalia » 25 May 2018 20:04

I am not seeing any signs of cleaner contacting the underside f the platter and it seems nearly impossible that the spray got under there considering the location of the buttons in relation to the underside of the platter.
I am attaching some fotos of the deck with the platter removed and I have a screwdriver pointing to what must be a sensor that read something on the underside of the platter and even that is a long way from where I was spraying and was covered up by the platter when I was spraying. I didn't go crazy with the spray and shot liquid all over the place when I was using it. I only sprayed along the sides of the buttons. In one fotos I have attached you can see two items, a resistor? and a capacitor? That look like they may have melted down or maybe this is how they came from the factory.
Hopefully these fotos Help shed some light on what direction I should head in besides to Ebay looking for another turntable. [-X

Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Re: Turntable starting spinning backwards

Post by Surfalia » 25 May 2018 20:34

20180525_141702-01.jpeg
(137.61 KiB) Downloaded 100 times
20180525_141743-01.jpeg
(262.97 KiB) Downloaded 100 times

Coffee Phil
vinyl addict
vinyl addict
United States of America
Posts: 5379
Joined: 20 Sep 2008 08:22
Location: California

Re: Turntable starting spinning backwards

Post by Coffee Phil » 25 May 2018 22:46

Hi Surfalia,

This turntable seems too nice to through into the bin. If you spin it by hand in the right direction when starting it, will it continue in the right direction? If so that may get you by until this is sorted.

To trouble shoot this further will require a service manual. One of the models in the library may be similar enough for its manual to be useful. There are adjustments on the board for gain and phase. To adjust these will require the manual and very likely an oscilloscope.

Do humor me and show the underside of the platter.

Phil
Surfalia wrote:
20180525_141702-01.jpeg
20180525_141743-01.jpeg

Surfalia
junior member
junior member
Posts: 6
Joined: 24 May 2018 06:47

Re: Turntable starting spinning backwards

Post by Surfalia » 25 May 2018 23:30

That request almost sounds a scene. Do you think I am just another turntable whore thst you can just take for a spin. I do not show the underside of my platter on the first date [-X
Alright my mom says its o.k.

If anything you might see an oily fingerprint on the platter but that's about it. There is a kind of wear mark on each spoke of the underside where I suppose that sensor looking component has been making contact as the platter spins
20180525_171731-01.jpeg
(145.2 KiB) Downloaded 90 times
20180525_171712-01.jpeg
(148.63 KiB) Downloaded 90 times

Coffee Phil
vinyl addict
vinyl addict
United States of America
Posts: 5379
Joined: 20 Sep 2008 08:22
Location: California

Re: Turntable starting spinning backwards

Post by Coffee Phil » 26 May 2018 03:32

Hi Surfalia,

I forgot to mention the the resistor and cap are probably like that from the factory. They are probably an afterthought. If boards have been made they are not going to dump them for a small change. They will cut and jumper traces and add parts with adhesive.

This appears to be a similar machine for which there is a manual:https://www.vinylengine.com/library/Sony/ps-x35.shtml

The magnetic stuff on the bottom of the platter appears to be oxide similar to magnetic tape. In any case it is the speed sense. If the platter spins at correct speed it is likely fine.

The commutation is handled by Hall sensors which do have adjustments associated with them. They are on the board in near the motor rotor. I can easily believe these will effect startup direction. Adjustment will require a scope so either get one if you feel you can do it or find a friend with one who can understand the procedure in the manual.

If the machine runs in the right direction after hand starting it, just do that until you are sure you can find someone who can adjust the pots near the Hall sensors. I recommend NOT messing with the pots without a scope and an understanding of the procedure.

Phil

Surfalia wrote:That request almost sounds a scene. Do you think I am just another turntable whore thst you can just take for a spin. I do not show the underside of my platter on the first date [-X
Alright my mom says its o.k.

If anything you might see an oily fingerprint on the platter but that's about it. There is a kind of wear mark on each spoke of the underside where I suppose that sensor looking component has been making contact as the platter spins
20180525_171731-01.jpeg
20180525_171712-01.jpeg

Post Reply