In "William Sommerwerck"
wrote:

Now when first powered on after an overnight rest, it will shut off
immediately (stays on for maybe 5 seconds). After power cycling
the main switch (can't be done via remote -- must use the switch
on the back), it will run all day without problem.

That might very well be the defining symptom. What is the circuit
difference in the way the unit turns on and off via remote, and by
flipping the switch?

When it's turned off by the switch in the back, it's really off, just as
if you'd pulled the plug.

When you turn it off with the remote, some parts of the set are still
on, at least enough to allow it react to the remote. This means that the
power supply is still doing something, or at least trying to.

--
Bert Hyman St. Paul, MN