Tried some RS freeze spray on the TDA1541 chip - made no audible difference.
I'm nervous of desoldering the chip. I have a desoldering station but I'm finding that some components take quite a lot of heat to be able to fully desolder the pins.
I do have some 28 pin sockets. My plan, if I can do it without destroying both of the TDA chips I now have, would be to desolder the TDA chips in both 206s, fit sockets and then swap the chips over between the boards.
Is there any way, without having access to an oscilloscope, of testing a TDA chip off-board, say to a basic functional level?