The compact disc or CD player was the first major entertainment appliance that used digital technology. It revolutionized the music industry, offering sound clarity unavailable on magnetic tapes--even the best. So when prices came down, the CD player became one of the most popular entertainment devices, now found in most homes and many cars.

How Does It Work?

A compact disc player uses a central motor to rotate the disc while the lens reads digital information imprinted on the bottom of the disc.

A CD player is an electronic device powered by a universal motor that rotates a flat plastic disc that has been stamped with a digital code representing specific sounds. As the player rotates the CD at high speed the sound track--less than the width of a human hair--is read by a laser beam used to produce an electric stereo sound signal. This signal goes to an amplifier and speakers or earphones to reproduce the music represented on the CD.

What Can Go Wrong?

CD players either work or they don't. The third option is that they work, but the sound skips--which typically is caused by a dirty or damaged disc rather than the player. CD players have few moving parts and are mostly trouble free. In fact, there is little you can do besides clean the CDs, clean the machine, or replace cords. Just about everything else should be turned over to an electronics technician.

Fix-It Tip

You can use a CD repair kit, available where CDs are sold, to polish out scratches on the underside of the disc.