LINN Axis Turntable Motor

Need help on the Linn Axis Pully Motor:
Initially I found that the motor has a hard time starting up. Even with turning the platter by hand, it only revolves a short time and is slow on 33rpm, then stops and little to none on the 45rpm speed.

I have replace ALL electrolytics caps, replaced the R1 resistor with an uipgraded thermistor and the rectifier also upgraded, new drive belt and re-oiled the subplatter well as recommended by a Linn service person.

Still the platter does not rotate freely and eventually stops. The motor has a vibratory noise and sometimes starts backward.

Is the motor shot or some other parts needs replacing. Please help. Thank you
Tony
 
I think the clue here is that sometimes the motor runs backwards. This suggests that you have probably lost one "phase" from the Axis PSU. Get a meter on AC volts across the two phases and I think you will find either one of them absent, low in amplitude, or distorted.

The cause of this is most likely in the output stage itself. Probably a BUX85F.

Do you have a scope?

If you have one phase absent, I'd check the o/p transistors on ohms range and replace as necessary. It may be prudent to replace the associated drivers at the same time. BC184?

This circuit is a bitch to fault find on, and please beware as it is not isolated from the mains and will bite if not treated with proper respect.