WEIRD CD player problem

[bill]

I have a Sony CDP-302 player
this is an old, ~1986, high end player.
It playes very well --- as long as it is tipped to and angle of 45° or
greater on either side. Not 40°, but 45°, maybe 43°. I measured it.
If I tip it from 40° to 45° it will start working. No bumping or
jarring required.

If it is flat or tipped to any angle front to back, the spindle motor
won't operate. The spindle motor circuit doesn't get any drive signal.
I traced it back to the electronics board and something is shutting
down the generation of the signal. The problem is on the CD carriage,
because I loosened the electronics board and tipped them seperately.

The spindle motor is an open DC type. Coils are on the PC board with
the magnet attached to the bottom of the spindle. NOTHING appears to
be loose or jammed. All micro switches seem to be operating in all
positions. It worked intermittently in the flat position for a while.

It is suppose to spin the CD on insertion or power on and read the
TOC, then stop and wait for the play button. It does this only when
tipped at the proper angle.

I don't have a schematic, but what would be position sensitive to shut
down the drive signal?

thanks

 

[bill]

sorry - got it in the wrong group

 

[Shenan Stanley]

I have a Sony CDP-302 player
this is an old, ~1986, high end player.
It playes very well --- as long as it is tipped to and angle of 45°
or greater on either side. Not 40°, but 45°, maybe 43°. I measured
it. If I tip it from 40° to 45° it will start working. No bumping or
jarring required.

If it is flat or tipped to any angle front to back, the spindle
motor won't operate. The spindle motor circuit doesn't get any
drive signal. I traced it back to the electronics board and
something is shutting down the generation of the signal. The
problem is on the CD carriage, because I loosened the electronics
board and tipped them seperately.

The spindle motor is an open DC type. Coils are on the PC board with
the magnet attached to the bottom of the spindle. NOTHING appears to
be loose or jammed. All micro switches seem to be operating in all
positions. It worked intermittently in the flat position for a
while.

It is suppose to spin the CD on insertion or power on and read the
TOC, then stop and wait for the play button. It does this only when
tipped at the proper angle.

I don't have a schematic, but what would be position sensitive to
shut down the drive signal?

Most drives work at any angle if they are in proper working order and this
players' age make me think it is just not worth the investment required to
attempt to repair or even actually figure it out. I agree completely with
the responder here:

http://www.diyaudio.com/forums/showthread.php?postid=468568

 

[bill]

Most drives work at any angle if they are in proper working order and this
players' age make me think it is just not worth the investment required to
attempt to repair or even actually figure it out. I agree completely with
the responder here:

http://www.diyaudio.com/forums/showthread.php?postid=468568

Well what's the fun in that???
This IS a very well built mechanism with linear motor and triple
lasers. I guess if I had a schematic I might figure it out.

It has to be mechanical, maybe the inside of a microswitch.
Never saw one go bad like that.