Turntable speed issues

[jason05216]

I asked this at vinyl engine and didn't get a response. Anyone have any thoughts?

I've got a Pioneer PL-516 TT that I've recently, 6 months ago, gotten out of storage and begun using again. I replaced the belt and everything was fine as far as the speed was concerned. Last night while playing an album the platter slowed really dramatically then came back up to speed. It ran a little longer at the correct speed then slowed again and didn't come back up to speed. I could adjust the platter speed but it wouldn't hold the speed. The platter seems to spin freely when I spun it by hand.



What would be things to check out? Is the motor failing?

I can get a motor and transformer on eBay. Is that a reasonable thing to replace or are there other things to consider?

[novisnick]

Jan 4, 2018 15:54:20 GMT -5 jason05216 said:

I asked this at vinyl engine and didn't get a response. Anyone have any thoughts?

I've got a Pioneer PL-516 TT that I've recently, 6 months ago, gotten out of storage and begun using again. I replaced the belt and everything was fine as far as the speed was concerned. Last night while playing an album the platter slowed really dramatically then came back up to speed. It ran a little longer at the correct speed then slowed again and didn't come back up to speed. I could adjust the platter speed but it wouldn't hold the speed. The platter seems to spin freely when I spun it by hand.



What would be things to check out? Is the motor failing?

I can get a motor and transformer on eBay. Is that a reasonable thing to replace or are there other things to consider?

Sounds like the motor is failing. Give Needle Doctor a call. They’ll be able to answer almost any questions you have.

[405x5]

Just let it run overnight....years of storage?
That might just do the trick with nothing to loose.

Bill

[KeithL]

All good suggestions.

The motor could simply be failing.... or its oil could have turned to glue.
However, note that the motor and belt don't actually deliver much power to the platter, so it doesn't take much friction to cause it to slip.

However, since you replaced the belt, there are a few other things I would suggest:
1)
Make sure you got the CORRECT belt (if the belt is too loose, or too stiff, it might slip).
2)
Make sure that you didn't get any motor oil, or even oil from your hands, on the pulley or the platter edge that contacts the belt.
(Oil on the belt may cause it to slip, particularly at the smaller motor pulley where the torque is highest.)
If you got oil on it, you can probably clean it with one of those alcohol lens-cleaner swabs.
3)
You said that the platter turns freely.... but have you actually oiled the platter bearing?

[jason05216]

Jan 4, 2018 16:40:05 GMT -5 KeithL said:

All good suggestions.

The motor could simply be failing.... or its oil could have turned to glue.
However, note that the motor and belt don't actually deliver much power to the platter, so it doesn't take much friction to cause it to slip.

However, since you replaced the belt, there are a few other things I would suggest:
1)
Make sure you got the CORRECT belt (if the belt is too loose, or too stiff, it might slip).
2)
Make sure that you didn't get any motor oil, or even oil from your hands, on the pulley or the platter edge that contacts the belt.
(Oil on the belt may cause it to slip, particularly at the smaller motor pulley where the torque is highest.)
If you got oil on it, you can probably clean it with one of those alcohol lens-cleaner swabs.
3)
You said that the platter turns freely.... but have you actually oiled the platter bearing?

I replaced the belt a while back. I think this belt has been on for at least 4 months. I'm as sure as I can be that this is the correct belt. It was the correct part number and it seems to fit fine. I did not oil the bearing. It looks to be a little tricky to get to but I'll give that a go. 

If the speed control potentiometer is going bad would that show up as a problem like this or would it have different symptoms?