"Greg" wrote in message
...
Hi Tim,
Thanks for the info. This amp has been modified I guess at the
factory as it was made mid 1997. The wires were soldered to the board
& covered with hot melt glue which I think is a bad thing. I have
removed both input screened cables & replaced as a precaution.
Sadly it has made no difference to the problem.
I am checking the ground connections but I still suspect the design of
the PSU is inherently unstable. I can induce the fault by switching on
my heat gun & holding over the PSU board. I was trying to see if the
problem is heat related but it seems not.

Clifto - I don't understand your comment. I have replaced the screened
cables as described above but are you suggesting the power leads need
screening too?

Best regards,
Greg.

If the glue is at all browned, remove it.

Mark Z.