I have this Sony 3CDs exchanger stereo since many years. It has never played writable cds but when it started to get stuck with original cds (few years after new) i opened it and i applied grease over the gears and over the little rail that holds the laser device and then it worked fine with all original cds. You should buy electronics grease for your cd player, but if you can´t find it you can apply some of other device such a joystick or even grease residues of the same player you´re trying to repair.