Why are all of my three TVs suddenly experiencing pixelation? This is very disturbing. Reset all boxes. Reset battery in main box. Checked all connections.
It could be the splitter or the ONT. Each is common to all three TVs.
The battery in the ont isnt going to do anything since its for the phone line.
Since its happening on all 3 of your tv's your signal is coming in to low (or to high as it can happen with signals way to high as well).
As already said it could be your splitter or the ont.
If you google how to access the hidden menu on fios dvr/set top box you can find how to check your signal coming in from the ont to the box. If its low check any splitters you might have before ruling out the ont itself.