On 14 Apr 2004 03:39:41 GMT, (LASERandDVDfan)
wrote:

I have a philips AK601 CD player which will not open its drawer.
Before this the drawer would close immediately after opening, don't
know if this is part of the problem.


Did you check the belt which drives the mechanism? Also check the condition of
the limit switches which tell the CD player's syscon whenever the drawer is
open or closed. - Reinhart

belt is ok (can keep motor still even with +5V over it)
Switch is ok too (one switch for open and closed detection)

It's the second part of my posting that is interesting...

I found out that the motor which opens the door gets +5 volts
initially to close the door. After that it keeps getting +5 volts.
When I push the open/close button on the frontpanel the voltage drops
to about +2 volts. I think it should be a negative voltage to let the
motor run the other way to open the drawer.

What could be wrong?

I found that the voltage drop is only for a second or so. Since I'm
using an analogue multi-meter for voltage testing, it is just not fast
enough to show the complete voltage drop.
during that second I can see the motor trying to run in the other
direction (the direction to open the drawer, or perhaps only loosen
tension on the belt after the +5V drops to a lower voltage, which
causes the axle of the motor to move a little)

When I manually push the drawer (partly) open immediately after the
voltagedrop, it seems the voltage is between 0 and +1 volts for about
4 seconds.
After that the voltage becomes +5V again, which causes the drawer to
close. When it is closed, the voltage stays +5V. (should be 0 I
think?)

Also I checked the voltage on another Philips (different model) CD
player. It gets -5V immediately after pressing the OPEN switch on the
front. This causes the motor to run in the other direction to open the
drawer.

The defective one just doesn't get the negative voltage.


Any ideas?

Eelco.