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PS-LX350H Sony Turntable no motor movement

Brynnpr1

Nov 7, 2022
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I have a Sony PS-LX350H TURNTABLE. It just stopped turning. the motor shaft doesn't move. I opened it up, checked for 6 volts coming out of the transformer....nothing. /checked voltage going in and it was 125.4v. Got a new transformer.....still no movement of the motor shaft I found a capacitor? on a pc board that looks like it exploded!?!?
Can anyone help?

Bob P
 

kellys_eye

Jun 25, 2010
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Nope - not exploded. Just held down with nasty looking glue and insulated by some crappy tape - what a poor 'mod'!!!

Are you supposed to get 6V out of the transformer? and are you getting it now?

Post pics of the whole board and the wiring to/from it.
 

repratt1

Nov 10, 2022
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Nope...only have 1.6mV....here's the photo.
 

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repratt1

Nov 10, 2022
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Nope - not exploded. Just held down with nasty looking glue and insulated by some crappy tape - what a poor 'mod'!!!

Are you supposed to get 6V out of the transformer? and are you getting it now?

Post pics of the whole board and the wiring to/from it.
Have any additional thoughts?
 

kellys_eye

Jun 25, 2010
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Check the fuse on the pcb adjacent to the transformer. Show a close up of same pcb.

Many small transformers have internal thermal fuses as well as secondary (external) fusing. If the internal thermal has blown you need a new transformer - unless you're lucky enough to see the thermal on the side of the transformer winding and can successfully remove/replace it???
 

repratt1

Nov 10, 2022
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Check the fuse on the pcb adjacent to the transformer. Show a close up of same pcb.

Many small transformers have internal thermal fuses as well as secondary (external) fusing. If the internal thermal has blown you need a new transformer - unless you're lucky enough to see the thermal on the side of the transformer winding and can successfully remove/replace it???
Here's photos of the transformer (this is a replacement that I bought on ebay) and the pcb where there is a fuse. I checked that first thing....it's good.
 

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Bluejets

Oct 5, 2014
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Find it difficult to follow your logic...if zero out on the transformer and you have a new one, did you fit and test that......???

That aside, new one appears to have multiple outputs...is it the correct replacement...???
 

kellys_eye

Jun 25, 2010
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I'm assuming the transformer with the brown/white leads is the original? The brown/white are the mains input and the yellow is the secondary.

The new transformer has yellow secondary leads too, the primary has red and 'some other colour' (I can't see). Assuming you connected it correctly (not reversed the primary and secondary windings) and your meter is set to read AC and not DC, please confirm that this is correct and that you still cannot measure AC volts at the YELLOW wires...?
 

repratt1

Nov 10, 2022
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The transformer in the photos is the original. The 'part #' on the original and the replacement are the same...almost. The original one had a third wire on the input side next to the brown and the white wires. It was red and terminated and capped. When I installed the replacement transformer, I connected the brown to brown and white to white. The replacement didn't have a red wire.

That's right, I am confirming that I connected the replacement transformer brown to brown and white to white. However, upon checking the voltage output from the transformer, I now get 15.5 vac! The motor still does not turn on.

Thanks for being patient with me.....I wish I knew more about this.....I just like this turntable a lot and can't afford to replace it at $200 plus. I may have misread my test of the original transformer and it may be fine, therefore, the problem is with something else.

Bob
 

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Bluejets

Oct 5, 2014
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. The 'part #' on the original and the replacement are the same...almost
If original was 6 volt and the new one is giving 15vac then clearly it is NOT the same.

From your last statement, it is clear you need the local assistance of someone with some basic meter reading and electronics skills.
 

repratt1

Nov 10, 2022
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If original was 6 volt and the new one is giving 15vac then clearly it is NOT the same.

From your last statement, it is clear you need the local assistance of someone with some basic meter reading and electronics skills.
Understood. I thought that you guys would be able to do the same research I did when I found the '6 volt' info....I just don't remember where I got that from or I would go back and check it for accuracy. I'm now thinking it was wrong and that 15 vac is correct.....so I will just have to re-trace my steps. The transformer is the same. Thanks for your time. I've been reading meters and building computers for 30 years.
 

Bluejets

Oct 5, 2014
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......but.. but ...but..you said nothing out originally ...goto ( latter part)#13...
 

kellys_eye

Jun 25, 2010
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The AC goes to the main PCB via the yellow wires so if the AC is present and the motor still isn't turning then you need to follow the supply wires to that PCB, remove it, photograph it and post it here.

Is the platten 'direct drive' or is it via a belt?

guessing here - but the board with the two blue 'boxes' on (they are relays) looks to power the motor (the silver 'disk' with white/black wires attached). That board seems to have circuitry associated with platter speed (45/33rpm probably) and the relays 'choose' which speed (all guess work).

Give the relays a sharp tap with something solid (small screwdriver handle) to see if the contacts are dodgy....
 

repratt1

Nov 10, 2022
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The AC goes to the main PCB via the yellow wires so if the AC is present and the motor still isn't turning then you need to follow the supply wires to that PCB, remove it, photograph it and post it here.

Is the platten 'direct drive' or is it via a belt?

guessing here - but the board with the two blue 'boxes' on (they are relays) looks to power the motor (the silver 'disk' with white/black wires attached). That board seems to have circuitry associated with platter speed (45/33rpm probably) and the relays 'choose' which speed (all guess work).

Give the relays a sharp tap with something solid (small screwdriver handle) to see if the contacts are dodgy....
Sorry..I've been away for a few days and came home with the flu!@#$%

With the turntable plugged in, I can feel and hear the relays making a sound and movement when I activate the switch that begins the platen's revolutions. Just in case, I did give them a sharp tap several times to see if they were sticking. No change....no movement of the motor shaft. I don't know if that rules out 'dodgy relays' or not. I guess checking the voltage to the motor would be the next step, yes?
 

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repratt1

Nov 10, 2022
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I checked the voltage at the motor.....power turned on, switch for turntable rotation not activated, result "0.0 voltage". When I press the activation switch I hear the relays and the voltage rises to "4.9 mV"......thats all. It's a 6 volt motor. Backing down the path, I guess it could be the relay board, if not then it could be the next pcb with the speed adjuster on it.

I'm at a loss for what to do next......maybe look for a used one for sale!?
 
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