Yamaha PX-3 won't advance

[Brian Henkel]

I have a Yamaha PX-3 that seems to work for all but advancing the arm toward the center of the record. I took apart the tonearm transport and removed and cleaned all of the belts. I also took every switch apart and cleaned them with contact cleaner. They slide beautifully. It powers on, the speed switch works, the cut switch works, the move right switch works, The 17 and 30 auto play switches light when depressed. The repeat switch does not light up and the advance button does nothing. If I move the arm manually toward the center of the record the platter starts. If I press the down button it will play but the arm never advances. The motor is never activated to move the arm. Any ideas?

 

[Ken Boyd]

Check to see if their is voltage at the motor with a meter when you push the arm advance button.

That might help to determine if you have a motor problem.

 

[Brian Henkel]

Check to see if their is voltage at the motor with a meter when you push the arm advance button.

That might help to determine if you have a motor problem.

I was able to verify that I have 3.3 volts going to the motor when the arm is manually moved toward the center and I depress the move right button. The arm moves back toward rest as it should. When I depress the advance button with the arm still part of the way toward the center of the record and my multi-meter leads on the same solder connections, there is no voltage.

There are some optical sensors and a switch at the end of the travel rails for the tonearm. Could they be stuck and interfering with the circuitry that would advance the arm?

 

[Ken Boyd]

I was able to verify that I have 3.3 volts going to the motor when the arm is manually moved toward the center and I depress the move right button. The arm moves back toward rest as it should. When I depress the advance button with the arm still part of the way toward the center of the record and my multi-meter leads on the same solder connections, there is no voltage.

There are some optical sensors and a switch at the end of the travel rails for the tonearm. Could they be stuck and interfering with the circuitry that would advance the arm?

I don't think the sensors would play a part when you push the advance button unless it was at the very end of the runout. If I get your post right the button does work when you want to return the arm to the rest, but it doesn't work when you want to advance the tonearm towards the record, and that is because you don't have any voltage at the motor when you press the button. That button if it is the same as my PX-2 has two positions if you push it lightly it advances slowly, if you push harder, it advances at a faster pace, so it must have a two position switch, and you would get two different voltage readings depending on if you push the button softly or push harder on it. If you have some contact cleaner you might try cleaning the contacts in the switch that moves the advance motor, and you will probably need to see if their is voltage coming into the advance switch. It sounds like if I get your post right that the return switch is working?

 

[Ken Boyd]

Here is a link to Vinyl Engine they have the owners manual, the schematic, and the shop manual, no charge, you just have to register.

 

[kaplang]

I have a simular problem with my PX2 that seems to be tempature related. When it’s cold and I press the play button the arm does not move till I push it gently twords the record and then it’s fine from that point on. I’ve cleaned the and retensioned the belt springs but it hasn’t helped.

 

[Brian Henkel]

I don't think the sensors would play a part when you push the advance button unless it was at the very end of the runout. If I get your post right the button does work when you want to return the arm to the rest, but it doesn't work when you want to advance the tonearm towards the record, and that is because you don't have any voltage at the motor when you press the button. That button if it is the same as my PX-2 has two positions if you push it lightly it advances slowly, if you push harder, it advances at a faster pace, so it must have a two position switch, and you would get two different voltage readings depending on if you push the button softly or push harder on it. If you have some contact cleaner you might try cleaning the contacts in the switch that moves the advance motor, and you will probably need to see if their is voltage coming into the advance switch. It sounds like if I get your post right that the return switch is working?

Yes, I think you have the general idea. One other thing that does not happen is there is no advancing of the tonearm while playing a record. It should be automatically moving along the record while playing. That also doesn't happen and I'd assume there is no voltage to the motor at that time either.

Thanks for the Vinyl Engine recommendation. I have all the manuals and schematics. I'm going to look through all of it but I'm not hopeful that I will be able to sort out for myself by reading up but you never know!

 

[kaplang]

Yes, I think you have the general idea. One other thing that does not happen is there is no advancing of the tonearm while playing a record. It should be automatically moving along the record while playing. That also doesn't happen and I'd assume there is no voltage to the motor at that time either.

Thanks for the Vinyl Engine recommendation. I have all the manuals and schematics. I'm going to look through all of it but I'm not hopeful that I will be able to sort out for myself by reading up but you never know!

PM Sent

 

[Ken Boyd]

I have the PX2 and have worked on mine, not the simplest table to work on, but they are IMO one of the better LT tables made.