CD players are highly sensitive devices that use a laser or optical lens to read information burnt onto a disc. CD players will commonly fail to read discs or skip when foreign objects such as dust or pieces of dirt get inside the machine. It is easy to regard these easy fixes as a major problem that requires discarding the machine. However, most CD fixes are cheap and easy to do and will cost much less than a new machine.
Inspect the disc you are attempting to play to determine whether it is scratched or dirty. Repair it with a CD repair solution according to the label instructions or clean it with a lint-free cloth.
Inspect the CD read head if the disc spins, but the machine never finds the first track or skips frequently when the CD is cleaned. Remove the top of the CD player. Simply remove the screws that hold it in place with a screwdriver. The location and number of screws will depend on the audio player model.
Look for a small circuit board that sits near the CD tray and the optical lens arm. Look for the potentiometer on the circuit board, which looks like a small plastic square with a plastic disc on top.
Mark the current location of the potentiometer on the circuit board using a magic marker, in case it needs replacing.
Reposition the potentiometer slightly with a screwdriver. Loosely replace the top of the CD player and test a CD. Keep repositioning the potentiometer until the CD plays properly. If it never does, you may need to replace the player.