On Mon, 17 Sep 2018 08:30:14 -0700 (PDT), "
wrote:

On Monday, September 17, 2018 at 11:02:07 AM UTC-4, Chuck wrote:
I don't have a service manual for this receiver but I checked the 6V
standby voltage and the 15V line from the standby power supply and
they both are at the correct voltage and have low ripple. I've heated
and cooled the boards with no change of symptoms. The problem began by
the receiver turning on in the middle of the night. Reset the micro
but it happened again 2 hours later. Now it clicks off when on from
anywhere from 2 seconds to hours. Is there a common fault for this
receiver causing these symptoms? Thanks. Chuck

Silly suggestion - does a piece of black tape over the IR sensor help at all? I suggest because I am seeing lots of "smart house" stuff starting to interfere with some legacy equipment out there. You might also isolate the remote as some of the touch-pad contacts may be aging and making random contact. That is to get past the obvious.

Otherwise, I would trace out the on/off circuit and look for a bad capacitor on in that lot. This unit is approaching 18 years old, or so, about the time these tiny little electrolytics start to fail.

Best of luck with it!

Yes, I covered the IR window but I didn't disconnect the IR receiver
which have caused weird tv symptoms. Thank you for your suggestions.