Sony DJ9000 Turntable

MisterBill2

Joined Jan 23, 2018
6,997
Hi
Have a problem with my Sony Turntable, when I switch it on the motor is just wobbling backwards and forwards anyone any idea as to what the problem could be .

cheers

Spike
This turntable uses a 3-phase brushless motor. If it is not starting, only dancing, then one phase is not being driven. First, check the motor resistance, it should be very close to the same across each set of 20 leads, showing that the motor is OK. Then carefully examine the motor connections back to the motor board for one failed connection.
The other things are checking the supply voltage to verify it is correct.
One last thing is to try to spin the motor by hand and see if it will run then.
It might also be a failed hall device position sensor on the motor board. And this system also has a forward/reverse detector, and if there is a problem with that it can act really strange.
I did not read the whole manual, there may be more diagnostics in it.
 

Thread Starter

spike1947

Joined Feb 4, 2016
177
This turntable uses a 3-phase brushless motor. If it is not starting, only dancing, then one phase is not being driven. First, check the motor resistance, it should be very close to the same across each set of 20 leads, showing that the motor is OK. Then carefully examine the motor connections back to the motor board for one failed connection.
The other things are checking the supply voltage to verify it is correct.
One last thing is to try to spin the motor by hand and see if it will run then.
It might also be a failed hall device position sensor on the motor board. And this system also has a forward/reverse detector, and if there is a problem with that it can act really strange.
I did not read the whole manual, there may be more diagnostics in it.
Hi
Thanks for your reply, ok will check those out, it will not run if I spin it by hand ! .

cheers

Spike
 

Thread Starter

spike1947

Joined Feb 4, 2016
177
Sorry Guys was checking the motor without the platter on ( reason was told the platter will not self start , needs a push)

Still the same though, not self turning .

Spike
 

MisterBill2

Joined Jan 23, 2018
6,997
Sorry Guys was checking the motor without the platter on ( reason was told the platter will not self start , needs a push)

Still the same though, not self turning .

Spike
Does that mean that if you give it a push it will keep running? That is interesting. and does it run smoothly, or does the thingput a warbling effect on the music? You may have one phaes not driving right. That could be an open winding, a failed driver IC, a failed hall sensor, or a broken connection someplace. or even a cracked circuit board or bad solder connection/
 

Thread Starter

spike1947

Joined Feb 4, 2016
177
Does that mean that if you give it a push it will keep running? That is interesting. and does it run smoothly, or does the thingput a warbling effect on the music? You may have one phaes not driving right. That could be an open winding, a failed driver IC, a failed hall sensor, or a broken connection someplace. or even a cracked circuit board or bad solder connection/
Hi
Thanks for your reply , yes it does run ok when given a push and the strobe line is ok, checked all the winding's and they all read the same, platter bearing is smooth ( re oiled), will check again trans output and note measurements against drawing.
Cheers
Spike
 
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