Sony CDP M-35 Can't spin up correctly

stoneman · Joined: 03 Aug 2006 Posts: 3 Location: Ottawa, Canada

Has anyone had experience with this CD player. It will not spin up to speed most of the time. Occasionally after many "motor kicks" from the driver it will start up and play just perfectly. If I spin up the platter by hand (while the driver is giving little bursts) to nearly the correct speed it seems to work fine. I cannot find a service manual on this site for this machine, but I know it is the smaller version of a larger one that may be on the site but I do not know the number.
Any help would be appreciated.

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

measure the impedence of the spindle motor, it should be approx 12-14 ohms at all points, if it isn't replace it.

stoneman · Joined: 03 Aug 2006 Posts: 3 Location: Ottawa, Canada

Thanks Gary, I will try that.
"At all points" confuses me. Do you mean at the different connection points in the circuit or something else?
I will disconnect the motor board from the control board and measure it statically but do you mean to measure it dynamically?

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

AT ALL POINTS OF ROTATION. IE MEASURE, ROTATE SLIGHTLY & REPEAT AS SOMETIMES THE RESISTANCE WILL BE LOW ONLY IN CERTAIN POSITIONS

Guest · Posted: Fri Aug 04, 2006 2:50 am Post subject:

Thanks, that explains it.
Why would the resistance change (go lower I assume) over time?

stoneman · Joined: 03 Aug 2006 Posts: 3 Location: Ottawa, Canada

that was me again Gary, asking the question. I forgot to log in.

Guest · Posted: Fri Aug 04, 2006 3:54 am Post subject:

I measured as you said. The resistance is about 11.3 Ohms, but jumps around when I move its rotational position. When I stop rotation at any position it goes back to about 11.3 ohms.
The adjacent head slide motor is the same part number (RF-310T-11400) and measures about 12.0 Ohms under the same conditions.
Does this explain the behaviour?