Sun Fire X4540 in a reboot cycle

So I have a lot of equipment in San Diego racks and there was a recent county-wide black out. Our data racks are supposedly on diesel generators. Most everything made it through the outage just fine without any issue.

But for whatever reason, one of our X4540's developed a quirky habit of rebooting itself constantly. It powers on and resets itself 1 second to 10 minutes later. This can happen as early as early as the BIOS splash screen (common) and as late as Solaris completely running (rare). It's not uncommon for a reset to occur during the memory check. But I'm cautious in reading too much into this.

I read the docs just briefly. And they do hint that the power supplies will restart or shutdown the system if power isn't within spec. I tried every permutation of multiple PDUs/powering left,right, or both power supplies and it made no difference whatsoever.

On the suggestion from Oracle support, I reseated just about every user serviceable component on the machine. And this didn't do much at all either.

Has anyone ever seen anything like this from a Sun Fire? Any help GREATLY appreciated.

Thanks,
Brian

looks like a hardware error to me... sadly such errors are hard to troubleshoot.

Have you checked that you don't have any error messages logged (boot permitting of course)? I just read over at another site of a similar case, where the user went through his /var/adm/messages although he didn't find anything strange there...
However, here's what he did:

"Digging out logs I found out there were critical errors about gdm so I disabled the service (svcadm disable svc:/application/graphical-login/gdm:default ) and the reboots stopped."

His symptoms were just like yours, on an X4540.

you should analyze the messages whichever you see in the bios bootup screen for hints, which might help.