UNIX for Advanced & Expert Users

Hello Everyone I run 4 HP 9000 servers with HP-UX 11.0 on all 4, with an Infomix Database. About 6 months ago one system starting acting real weird it will display the message that it lost power (which did not) and it would shutdown, Then roughly 30 seconds later it would then say power has been restored and shutdown process was terminated. This last rougly a month then the system went belly up and died. I had HP on site and they replaced EVERYTHING including the kitchen sink (LOL). Well since the complete system replacement it was working just fine. Well it has started doing it again weekly. I changed UPS with another machine that is not in use. Lasted 1 month now problem has returned. Is this now software issue and if so where should i look. All servers were loaded with same software and hardware. Can anyone please give me some ideas before i find the sledgehammer and give it the last rights ceremony. Sorry long wanted to give the history of this machine

How old are the UPS boxes? How are they communicating with the HP machine?

It may very well be that the UPS is failing - both of them. Industry standard is to replace the UPS units at least once every two years, if not more often (Assuming it's not an industrial-grade power-source, in which case you might want to have it serviced).
Have you also checked the serial (or however it's connected) cable, and the physical port on the back of the box? It either of these is flaky, you may get false reports of random power spikes / brownouts.

What kind of UPS is it?

My systems are less than a year old. The UPS is a HP Power Trust II LR. They are connected to the system with a 9-Pin data cable. The card was replaced when they did the whole system replace including the cable. Also when i switched ups with the systems. The one that was it was switched with has not once gave an indication there is a problem. i will see if it still could possibly be the card i will change it and see what happens. I will let you know more once i change the cards around. Thanks for the help so far

If HP replaced the UPS, the cable, and the computer as you say... then the problem must be with the power. Ask HP to put a power line monitor on the line supplying power to ups in question. This will record any power fluctuations. The power could be screwy enough to worry the UPS without actually dropping power.

HP did not replace the UPS it was everything within the server because i had multiple components that they were believing was the problem. Here is the list of items they replace: power harness, systems board, all four processors, lan card, power supply, all 8 fans, and backplane. Since the system would not boot up that was they came to the conculsion was to problem it just took them a month to figure it out. But i was very statisfied with their results i am just worried that it may be starting again. But i will let you know more once i find out more. Thanks
P.S. I have alredy had the line tested