This is an interesting discussion. As I read the posts I wondered if this is a remote location and if so that could complicate the effort to troubleshoot. Then I reread the original post and saw "Not this router, it was rebooted and when accessed with Console the start-up config was gone." So there is console access and that is very helpful.
Just to verify: using console access for show version and the config register is 0x102 and when you attempt show startup the config file is empty.
I have experienced the symptom that booting the router results in an empty config. But that usually turns out to be that the config register was 0x2142 (typically as the result of a previous password recovery). And changing the config register to 0x2102 (or to 0x102) would result in booting a complete config. But that seems not to be the case here.
I have also experienced the symptom that booting the router results in an empty config. And the reason sometimes was that the startup config really was empty. This is typically the result of configuring the router and shutting it down without doing a copy run start (or the equivalent write mom). But if this router was configured, shut down, given to the installation team who took it and booted it successfully and it ran for 305 days then it must have had a startup config when it got to the site.
One thought that occurs to me is the possibility that someone did access this router while it was running at the remote site and for some reason erased the startup config. Is that perhaps what happened?
The other possibility that occurs to me is that somehow the power problems corrupted the startup config. That would seem highly not likely but perhaps possible. If you do have the ability to open cases with Cisco TAC it would be good to open a case and see what they have to say.
HTH
Rick
