Sony WM-B52 Repair

When the LA4570 IC shorts out, it produces a loud oscillating noise, and draws a huge amount of current from the batteries. For the diagnosis, I isolated the power supply and regulator IC to make sure that it was functioning properly.

The first step in the repair process is to remove the LA4570 audio IC, and measure the voltages produced by the regulator IC.

Removing the audio IC is extremely simple, however they use glue on the component side, therefore a wedge is required to remove it.

Sanyo LA4570

I managed to find a seller in China that had the last stock of this audio IC, and bought two, as they were only 40 pence each. After soldering the new IC, the cassette player worked fine. In addition, I used a hot melt glue gun to seal the pins of the IC to protect them from damage should it ever be exposed to water again.

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