Sony WM-B52 Clock Module

The Sony WM-B52 has a solar powered digital watch module with stopwatch and an alarm function. This would have been extremely useful for athletes for timing their races.

One of the reasons why they made it solar powered was because a battery hatch would have been another potential entry point for the water. Consequently, they sealed the watch module under the cassette lid, and it operates independently to the cassette player. As the alarm was not functioning, I decided to look at the clock module. There are only four screws on the underside of the cassette compartment that secures the clock module.

This extremely popular Sony Walkman enjoyed a long production run, and everyone wanted one for enjoying music in the bath.

This is the detached clock module.

This is the underside of the clock module. There seems to be a metal plate secured with four screws.

The other side of the metal plate reveals a piezoelectric buzzer for the alarm function, and it seems to be OK, however, it explains why the alarm function was barely audible. A clever engineer would have sent the alarm signals to the headphones, thereby saving money and improving the function.

Although the clock is solar powered, the alarm function will only operate if there was enough charge in the batteries. Therefore, the watch will not be able to produce the alarm sound with a depleted battery. Many people who bought this player did not realise that the clock will need its battery replacing. This is just a standard watch battery and almost any of the same size will work. I got a card of batteries from a thrift store and it had many batteries that fitted and worked.

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