If a cassette tape snags, fish out the tangled portion from the cartridge with a bent paper clip. Lay the tape on a flat surface, press the wrinkles out with your fingers, then rewind it, using a pen cap to turn the reel.
It may be easier to get at a jammed tape by opening the cartridge: unscrew the cartridge or, if there are no screws, pry it open along the weld line (you won’t be able to reuse the cartridge). If a tape breaks, splice it, using a splicing kit from an electronics shop.
After repairing the tape, screw the cartridge together or fit the reels into a replacement case. Cleaning the recorder Weekly cleaning of your recorder (or after 10 playing hours) will make your tapes last longer. Oxide buildup from the tape onto the tape heads and guides eventually decreases sound fidelity. Also, magnetic buildup can, in time, cause distortion. To get rid of oxide, use a cleaning kit from an electronics store or swab the heads, capstan, rollers, and guides with cleaning solution (denatured alcohol on rubber parts, trichloroethylene on metal). Rid the tape head of magnetic buildup by running a demagnitizing cassette in the recorder as instructed. Never lubricate the mechanism.
Complex microcircuitry in cassette recorders makes servicing of electronic parts difficult. Major problems may call for professional repairs or even a new machine.