said by mj_sab:Thanks for the replies. First time, I've cracked open the ONT -- I don't have anything lit (including power) so maybe the ONT is dead?
If you check the power supply of the ONT, it may be lit. It's usually connected to a UPS (Power supply -> UPS -> ONT). If Power supply fails, it will be on "aux power" and that light will be lit if battery is still good.
ONT is pretty basic: basic power and light. If your ONT power supply shows lit, it's most likely on the far end since ONTs rarely fails. I have been working in the industry and have probably seen 10 ONT failures in tens of thousands. Since the entire area of my neighborhood (which includes several Comcast repairmen who live nearby) we see that there's no far end connectivity so a distribution is down.
Given the flickering lights, multiple surges, the distribution probably got hit and that's why Frontier was waiting for parts to come in on Monday.