While cassette deck technology is outdated thanks to CD and MP3 players, there is a growing contingent of music enthusiasts seeking to preserve analogue music technology. Among many common issues with older cassette decks, however, is the fact that their motors commonly stop working. Most cassette motors operate on a belt drive that relies on a rubber belt to turn the cassette deck's heads. If the belt breaks, the cassette deck stops working. Replacing this belt requires the partial disassembly of the deck.
Unplug the power cord from the cassette deck. If it has been running for a while, allow it to cool down for several minutes.
Locate the model number on the back of the cassette deck. Write it down and purchase a replacement belt for your cassette deck's motor according to the model number. You can purchase replacement belts online from independent electronics retailers.
Loosen all Phillips-head or flathead screws from the cassette deck's outer casing. Remove the outer housing from the tape deck to reveal the internal motor. You can identify the motor by its rubber belt.
Remove all belts from your cassette deck's motor. Some cassette decks use multiple belts. Grasp the rubber belt and stretch it beyond the grooves on the belt drive motor's wheels. If the belt is broken, examine the inside of the tape deck for any broken pieces of rubber and remove them from the deck.
Apply some rubbing alcohol to a clean cotton swab or rag. Wipe down the areas around the motor. Allow several minutes for the alcohol to dry.
Install the new cassette deck belt. Wrap the replacement belt around the belt drive motor. Make sure the belt is lined with the small lip on the belt drive.
Replace the cassette deck's outer housing and its retaining screws. Reconnect the power cable to the cassette deck.
A stretched belt can cause your cassette's speed to slow down, which greatly affects the tape deck's sound quality. Replace belts on regularly used tape decks every two years.