Does anyone have a service manual to the Fisher AD-850 CD player they
would be willing to sell? This is an early model from 1983 that I'd
like to get going. I need to repair an apparent control logic
problem. The laser reads the disc fine, but it seems to get stuck
reading the TOC. It will play the entire disc as if it's reading the
TOC. I suspect that either the TOC data isn't getting to the micro
controller, or that the RAM used to store the TOC is not working.

I can use it on paper, fiche, or a pdf.
Andy Cuffe

Andy,

Some old Fisher units would do this when the inside limit switch was dirty.
They would spin the disc then "wait" for the limit switch. If the switch
never made, then they just sat there, and yes, I think I remember the laser
"drifting" after a while. So try cleaning the limit switch.

Mark Z.


"Andy Cuffe" wrote in message
...
Does anyone have a service manual to the Fisher AD-850 CD player they
would be willing to sell? This is an early model from 1983 that I'd
like to get going. I need to repair an apparent control logic
problem. The laser reads the disc fine, but it seems to get stuck
reading the TOC. It will play the entire disc as if it's reading the
TOC. I suspect that either the TOC data isn't getting to the micro
controller, or that the RAM used to store the TOC is not working.

I can use it on paper, fiche, or a pdf.
Andy Cuffe

On Wed, 17 Nov 2004 05:14:36 -0600, "Mark D. Zacharias"
wrote:

Andy,

Some old Fisher units would do this when the inside limit switch was dirty.
They would spin the disc then "wait" for the limit switch. If the switch
never made, then they just sat there, and yes, I think I remember the laser
"drifting" after a while. So try cleaning the limit switch.

Mark Z.


Thanks for the tip, but it's definitely not the limit switch. The
pickup correctly hits the limit switch, then moves to find the start
of the disc. I've tried playing with the set screw for the limit
switch, but it doesn't help. It doesn't just spin the disc, it's
reading the disc and will play from start to finish in what looks like
TOC reading mode. There's never any audio.
Andy Cuffe