Ac power failed of E4500

Question

This week, our E-4500 server restarted 2 times automaticlly.
At first time,I can't find any error in /var/adm/messages
but I found some infomation in "prtdiag -v"
Most recent AC Power Failure:
=============================
Fri Sep 26 01:59:24 2005
Power Supplies:
Supply Status
0 OK
1 OK
2 OK
PPS OK
System 3.3v OK
System 5.0v OK
Peripheral 5.0v OK
Peripheral 12v OK
Auxilary 5.0v OK
Peripheral 5.0v precharge OK
Peripheral 12v precharge OK
System 3.3v precharge OK
System 5.0v precharge OK
AC Power OK
This time is as same as the server's restarting time.
So i think my ac power maybe had some failure though now it is ok.
I replaced my ac power.
Yesterday, the server restarted again.
I can't find any error in /var/adm/messages too.
when i check in "prtdiag -v", i get the infomation again
Most recent AC Power Failure:
=============================
Fri Sep 30 12:54:11 2005
Power Supplies:
Supply Status
0 OK
1 OK
2 OK
PPS OK
System 3.3v OK
System 5.0v OK
Peripheral 5.0v OK
Peripheral 12v OK
Auxilary 5.0v OK
Peripheral 5.0v precharge OK
Peripheral 12v precharge OK
System 3.3v precharge OK
System 5.0v precharge OK
AC Power OK
"Sep 30 12:54:11" is also the server's restarting time.
i confused. where is the true cause?
i must find the cause ASAP. Please help me!

Answer 1

With AC power faulures especially when you have 3 PSU in the server it is not always straight forward, and the first part you think of might not always be the one at fault. for example, it could be power cables, power strips in the cabs, a problem with the power distribution, etc.
What I would do to narrow down the problem is as follows.
1. Change all of the power cords
2. Move the power cords onto a power strip that either other servers that have not gone down are connected to. Or even better that is on a different UPS.
Once this is down try passing the server through diagnostics for 3 or 4 hours and record the console output, this might show something.