Power Surge damage to PC Equipment

[faqinel]

Hi All,

I am an IT Technician by trade and would welcome your theories on the following situation that I encountered today.

Today after an overnight powercut (believe a sub station went down temporarily) one our clients rang up to say there server wouldn't start. The server was attached to a UPS at the time of the power cut and since then they had attempted there own fault finding, i.e. swapped power leads, bypassed the UPS but could not get any signs of life out of the server.

When I arrived onsite the four remaining servers, various switches and other ancillary equipment were working fine and some running off the same UPS. I picked the server up and returned it to my workshop (offsite) thinking that would be the best place to swap out blown components. However on plugging the server in at our workshop, it booted first time without any apparent issues.

On returning to the customers premises the server again refused to show any signs of life. I tried various sockets both in the server room and in several offices around the factory and several different leads but to no avail. I even tried plugging a standard PC into the same sockets using the same power leads and this booted fine each time. Again I returned the server to my workshop and Bingo it booted first time.

I have since swapped out the power supply and motherboard and whilst I now get power to the motherboard, when onsite, the Server stubbornly refuses to boot (no BIOS screen or initial POST check).

Can any of the forum members postulate a theory as to why this server should boot without issue when plugged in to my workshop mains but not at the customers premises.

Thanks in advance for any light you can shed on this.

 

[chrish_1977]

Dodgy power lead, seems strange that it works fine in your sockets but not in the customers, would suggest getting an electrician in to test the cabling etc to make sure nothing else is wrong, can't really think of anything obvious is you have plugged other pcs into the same sockets and they are all cool

 

[dcelectrical]

maybe there is a special force field around the customers premises, if I read right the unit was plugged in to the UPS which in turn was plugged into the incoming final circuit(plug) this if my memory serves me correctly mean the UPS acts as a protective device, I would be inclined to look at the unit first then secondly at the ups, it might be that the power down has caused it to supply at a different voltage or frequency, but my gut is that its all in the server

 

[faqinel]

Hi Chris,
The symptoms onsite would suggest that a component is pulling down one of the internal dc voltages, hence replacing the motherboard. I know that there can be variation between incoming mains voltages. It's rarely a steady 240 volts. Would a high input voltage at my workshop, say 250v and a low voltage onsite be enough to cause the symptoms described. Bearing in mind that a PC psu has to provide 12, 5 & 3v dc within set tolerences?

DC - A forcefield? Lol. Is there a test for this? If I hide behind a hedge at night will it be visible? Should I wear a tinfoil hat? I've already taken a picture of the working server so the customer doesn't think I'm a loon!

Matthew