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Cassette decks are one of the most popular music formats in the world, though gradually being replaced by CD players. Newer decks feature reliable electronic circuitry making most problems likely to be with the mechanical parts. Periodic cleaning, lubrication and replacement of belts, as needed, will add years of service. Most electronic problems should he handled by a professional technician.

Cleaning and demagnetizing the heads

A tape recorder works by magnetizing particles of metal oxide, which are basically glued to the tape. Time and usage will cause the oxide to come loose and collect on the tape guides, capstans and pinch rollers causing the tape to move off its path and affect sound. Clean and demagnetize the heads after ten to twenty hours of use.

The best method is a head cleaning/demagnetizing tape. Some of these work dry, on others a solution must be added. This cleaning tape is then played-usually for 20 to 30 seconds. With most cleaning tapes, when you get to the end of the tape-usually after several cleanings-it is discarded and a
new one must be used. Rewinding and reusing may cause particles previously collected to be redistributed or scratch the heads and other parts it comes in contact with.

The other method is to use denatured alcohol or a special head cleaning solution, and with a cotton swab moistened in one of these, open the cassette door, turn the machine on, press play and hold the swab against the head, capstan and pinch rollers as it turns. This method only cleans and does not demagnetize.

Servicing the drive system

In order to do this, you will need to get to the belts. This is a general description of some of the steps that might be required based on the way most decks are built. Have a diagram of your cassette deck handy (if it came with
one).

1.. Unplug the deck and remove the housing (usually by unscrewing several screws either on the bottom, side or both). Disconnect the flat cables leading to the front panel and transport assembly, lifting one side, then the other.
2.. Turn the deck upside down. Remove the screws holding the transport assembly and front panel in place. Now turn the deck right side up and remove the front panel and transport assembly.
3.. Unplug the leads (make a note of where to replug them). This will allow partial disassembly of the transport and will expose the belts. Here, there might be a circuit board that needs to be removed. If so, take note of its position and-any other parts you might have to remove to access the drive belts-to be able to properly replace them.
4.. To simply clean the belts, turn the pulleys by hand while dabbing the belts with a cotton swab dipped in denatured alcohol. Do not touch the belts with your fingers as even the smallest amount of skin oil can cause the belts to slip.
5.. To replace a worn or cracked belt, make a diagram of the belt's path, then remove the old belt either by cutting it or pulling it off. With a pair of cotton gloves, loop the new belt and fit it over the motor pulley. Use tweezers, if needed.
6.. Thread the new belt over the pulleys with a small screwdriver and gloved fingers. Try not to overstretch the belt. Once on, rotate the pulleys to make certain the belt isn't twisted.
7.. To reassemble the unit, follow these steps in reverse.
Servicing the heads. If there is a problem with the heads and you have a single reversing head, let a professional do it. If you have simpler non-rotating heads, you can replace them.

1.. Disconnect the power.
2.. You might have to remove other parts to get to the head. If so, make notes in order to properly replace them.
3.. When you have access to the heads, remove the screws that attach the head to the transport. Label wires to properly connect the new one, then desolder wires.
4.. Install the new head. It must be demagnetized before use.
5.. Reassemble the unit and then align the heads. Play a tape while you adjust the azimuth screws (this controls the alignment). Listen for the best treble response if you are using a prerecorded tape, or to maximize the pitch, use a special azimuth tape.
For any other problem, or if you have problems performing any of these tips, consult a professional technician.