Troubleshooting; Disc Doesn't Spin - Sony CDP-CX235 Training Manual

Troubleshooting

The CD Changer can be divided into two main areas: The Changer mecha-
nism that selects the disc from the tray table and the CD disc Playback
mechanism that reads the track of information from the disc and pro-
duces audio.
The Changer mechanism periodically requires mechanical adjustment to
compensate for wear of parts over a time. This will make sure the correct
disc is identified and selected.
The Playback mechanism is more involved, requiring an understanding
of the playback details for efficient repair.
Failures in the playback mechanism can be classified into these symp-
toms:
•

Disc doesn't spin.

•
Disc spins but doesn't read the disc's table of contents (TOC).
•
No Audio.
Disc Doesn't Spin
Before the disc spins, the sled must be at home position, the laser must
be turned on, and focus must be found. All of these things can be checked
easily.
Sled
In the CD Mechanism, you will manually move the optical assembly away
from home position. When you power up the CD changer, the sled motor
will turn, moving the optical assembly to the limit switch. This proves the
sled assembly is basically OK. As you move the gears make sure they
move without binding. The limit switch must be tested with an ohmmeter.
The sled check procedure is as follows:
1. Shut off power by pressing the POWER button if necessary.
2. Locate the large white gear in the CD Mechanism and rotate it so the
optical assembly moves away from the spindle motor shaft (which is
the home position).
3. Press the POWER button and the optical assembly should return home.
(The tray table should also rotate at this time.)
When the optical assembly reaches home it should close the limit switch
and power to the sled motor will stop. The white gear should be free
(unpowered), proving the limit switch is OK. You can also test the limit
switch with an ohmmeter.
Laser
It is best to measure the laser brightness with the Leader model 8001
laser power meter. During focus search, the laser power is 0.03mW in
this model CDP-CX235 200 disc CD changer. The procedure is:
1. Remove the magnet assembly by pulling it outward at a 2 o'clock
direction.
42