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.
Once again thanks to everyone who pitched in to my post.
Here is the latest update:Cox has promptly dispatched another tech.yesterday to reassess situation.I ran TV all day with no problem detected.Technician didn’t detect any problem either but still performed “preventive” maintenance like replacing connectors and splitter which was nice.It’s second day that all TVs work normally with no intermittent pixelation or random signal loss.So,I’m going to rest my case with following diagnostic menu screenshots(P4,P8)As long as shown signal and S/N levels maintained by provider no issues on customer side will appear.
