CD Player Skipping And Running Backwards!

mr pig · Joined: 06 Dec 2006 Posts: 9

Hello.
I have a Micromega Leader II CD player (Which is based on a Pioneer machine I think) which uses a Phillips swingarm transport. For a few years now the player has often been reluctant to start playing the disk, takes a few goes to find the start, but it has now deteriorated.

When play is pressed the disk will spin, then the lazer head will flick back violently and bang off the rear of its slot and the disk will spin at high speed in reverse! If and when I does start to play it starts to distort and skip towards the end of the disk and going to the next track will cause the flick/spin trick to be repeated. I have no idea what could cause this bizarre behaviour.

I like the player so would be keen to fix it. Any help would be gratefully received. Thank you.

vtech · Joined: 08 May 2006 Posts: 1264 Location: USA

Based on your description, it is a typical problem with laser attempting to read the data & is simply unable to get a stable focus point in a closed-loop circuit. Depending on the design of the servo, it may translate to several different symptoms from knocking laser to spinning the disc backwards in an attempt to obtain constant velocity. On occasion, I have seen where the lens overshoots up and may lightly hit the spinning disc, leaving marks.

As an average user, just about all you can do is to try cleaning the optics and the spindle(where the disc is clamped). Just to make sure you are not having a dust/dirt issue and a can of compressed air is usually sufficient for this purpose.

It may or may-not improve, otherwise replacing the laser would be the next step which is not something for the average user to try--especially if it is radial based.

Guest · Posted: Fri Dec 05, 2008 10:47 pm Post subject:

Thank you,

Would it be simple job to replace the whole transport, if one could be found? I think it is a Phillips CDM 4, not sure which version. Information about these transports seems hard to find. A list of other players that contained it would be a nice start. Do you know if lasers for this old mech are still available?

I had a check earlier and the knocking only seems to happen with one particular disk! The difficulty in starting the disk can happen with any though.

Thank you again for your help.

Colin.