Hi!

From my experience onhttp://www.divdev.fsnet.co.uk/repair5.htm
probably not the TUX but some sort of firmware problem or a problem on the
front panel if its like those Sony XR-C5300
cant help more than that , its a "repair" job that got away

A friend of mine was repairing a radio using a similar TEA-series IC.
I don't recall the exact details, but the IC "seemed" to be doing most
of the right things while reception just never happened. When audio
did come through the set, there was a lot of hash and other noise in
the signal. Every other piece of circuitry checked out.

He replaced the IC and the radio sprang immediately back to life.

William