Thanks to everyone who spend time to reply and trying to help.Here my own “internal” investigation and conclusion.My initial guess about signal strength fluctuation seems to be the root cause of the aforementioned problem.
I have Cisco 8742HDC cable box.Today I started to document signal and S/N levels (Page 8) in diagnostic menu.Here is my observation:TV works normally stable and without any intermittent signal issue for all channels for more than two hours (from 10am to 12:30pm) with following signal Level and S/N ratio.
All would agree that we can put to rest cables and loose connectors issues at this point.
The next screen shot was taken when problem occured
That what was on the screen at the same time.
After monitoring for more than three hours I can attest no problem,no pixelation or any other issues when signal remains at 2dBmV and S/N =38/39dB.
Well done finding the manual and getting into the diagnostics. That would have scared most people away. Hopefully the data will help the technician narrow down the issue. Good luck!
