Here are ten things that will help you if your CD changer will not play or if they skip.
1) Before installing your CD changer ensure you have removed the transportation screws, (where fitted). These will be highly visible on the exterior of the CD Changer.
2) Ensure the angle mounting adjustment screws found at either side of the CD changer have been set correctly according to the angle at which the CD changer has been mounted. Consult your handbook for details.
3) Check to ensure that your discs are clean and not damaged. Try other discs in the position of the disc that will not play. For example if your CD changer is failing to play (disc 1) try a different CD (preferably an original CD) in slot No.1. This is especially true if you are using CD-R or CD/RW copied discs as these are often the culprits if a cheap CD-R is used. The other reason is if it has been burned at too fast a speed or if the copier had not finalized the disc completely.
4) If you have used Velcro to mount your CD changer, please ensure that you have mounted it horizontally. This is so that a larger surface area makes contact to provide optimum stability preventing your discs from skipping. CD Changer manufacturers recommend using the included brackets but we have never experienced problems using Velcro if you mount the CD Changer horizontally ensuring that it is solid.
5) Use a CD laser cleaner disc. These are available from any music store and when played in your CD changer will clean the laser and correct any problems of a dirty CD laser such as discs not playing or skipping.
6) If the changer magazine ejects, then power is getting to your CD changer, so this will not be the issue. So now disconnect the CD changer data lead from the CD changer and leave disconnected for 1 minute, then reconnect and test for correct operation. This will often reset your CD changer.
7) If you are using a CD changer that has an in-line fuse such as a Pioneer, check that this fuse isn't blown. If the CD changer has an earth fly-lead, check this has a clean, tight contact with the car chassis. The majority of CD changers have the live and earth wires built into the CD data lead.
8) If you are using an Alpine CHA-S634 CD Changer in conjunction with a KCA-130B (Ai-NET to M-Bus convertor), ensure the small switch found next to the “Eject” button has been set to position No. 2. The CD changer leads must be disconnected when moving this switch. Please consult your manual for more details.
9) If you are using a Kenwood CD Changer ensure the small switch, found next to the “Eject” button on some models, has been set to the correct position for the Kenwood radio model you have connected it to. Consult your handbook for more details.
10) If all the above does not remedy the situation, we'll have only three suspects left: A faulty radio, CD data lead or the CD Changer itself. The only way to rule out the CD changer and CD lead is by trying replacements one at a time. However, please ensure you have followed 1 to 9 above.
If the problem is still present after following all the above, please, consult a car audio expert.