we have NO access to the ONT. No, there is no way to get error codes from it on our side. That would require at least an hour on the phone with Verizon and a ticket upgrade to get to at least the second tier (the last two times they could only IM the second tier to ask them to check). At any given moment in time there is only (usually) one light. It's on. Unless the battery dies in which case the battery light comes on. This product is NOT designed to interact with the consumer in any way. The last thing verizon wants is someone trying to interact with the fiber. Whoa.
Poring through all the logs on all three servers would be fun, for someone in a jail cell, I guess. But for the rest of us that is thousands of lines of code that will be very unlikely to show a direct cause regardless of how many errors may occur.
If it happens again, we can clean out the logs and see if we can find a (much smaller) set of logs to peruse. If the client were to "stick with it" and wait for it to come up and kill it again a few times, we may be able to find a pattern. But he has moved on to a new server and this one is idle. Oddly enough, without so much as a hiccup in its network connection (he did use it for an hour a few days ago ... and it did not die ... so we have no idea at this point). But I'm not going to authorize a technician to spend 18-20 hours poring over logs trying to "get lucky" any more than I'd go looking for a diamond ring dropped from an airplane over the ocean.
In this case, we need a few more shots to be fired so we can watch for the smoking gun.