1990 Sony Walkman WM-FX10 AM/FM Radio & Cassette Player Repair

My wife has started getting into analogue cassette tapes, after her father gave her his old tape collection – as such, I decided to buy her a Sony Walkman for her birthday this February, so she could listen to them on the move.

I ended up buying an apparently “working” 1990 Sony Walkman WM-FX10 on eBay, with original headphones – this is one of the later 1990s plastic types, which features a built-in AM/FM radio as well as the cassette player, and is powered from two AA batteries.

It seemed to work fine at first, both the radio and the cassette player, with the exception of the fast-forward button, which didn’t control the tape at all. Then, after a few minutes of playing a tape, the cassette player seemed to give up completely – no response from fast-forward, rewind, or the play button.

I decided to open the unit up, to try and determine whether this was an electrical problem or a mechanical problem. The WM-FX10 is a plastic clamshell case which is held together with a series of plastic clips – these need to be popped apart one-by-one, starting with the battery compartment and cassette compartment.

I opened the case up, and lo and behold, the drive belt fell out of the unit – not good! It had obviously deteriorated and stretched with age, so needed to be replaced.

Luckily, I had a suitable replacement in stock from a rubber drive belt assortment that I bought some time ago, albeit a bit thicker than the original – it’s important to install the belt under and not around the left-most spindle, else it gets trapped in the case.

I inspected the rest of the mechanism and the electronics to try and spot any other issues, but I couldn’t see anything obvious – these 1990s Walkman units use through-hole electrolytic capacitors which seem to be far more reliable and less prone to leakage than the SMD parts used in the 1980s units, so these didn’t need to be replaced.

With the case refitted, the Walkman’s cassette player now seemed to work perfectly, and the audio sounded great – a nice, quick (though fiddley), and cheap repair!