responding to http://www.electrondepot.com/repair/tda7295-145354-.htm , mark g
wrote:
Thanks for all the above replies. I'm very grateful.

The measurements I reported were made using the pointed tip of an oscilloscope
probe
and I thought I had been on pins of the chip, but I agree, the negative
voltages do suggest
the positive supply is missing.

What I forgot to mention was that the circuit actually worked for a few
minutes.
Prior to, and after that brief period, the symptoms were the same, i.e. as
described earlier.
It does rather suggest a bad joint, doesn't it, but I couldn't sort it out.

Anyway, I'll investigate again and let you know.