Machine dead after power outage. Why, and what to do?

[stumpinator3]

Yesterday morning there was a blackout while I was using the computer. The UPS kept the machine going while I saved the file I was working on, then shut the machine down normally, no problem. I turned off the UPS and unplugged everything from the wall. The power was on by then, but around here outages tend to come in a series, so I left things as is, then went to work.

When I came back, the computer was completely dead, in which state it remains. About all I can add to that is if I connect the power cord to the wall outlet and keep my ear close, I can hear a brief crackling, so I guess it’s drawing something.

Two questions:

(1) Why did this happen? At no time was the computer, or anything connected to it, unprotected. (Except for the printer, which is plugged directly into the wall outlet and connected by usb, and it was unplugged when I left.)

(2) Any ideas about what to do next? Try replacing the motherboard, or what? How do I track down the problem when the machine isn’t giving me any clues?

Here are the components, in case it makes a difference:


ECS 865PE-A motherboard
Powerware 5115 UPS
Pentium 4 3.06 Ghz
4 gig DDR 400 Crucial ram
PC Power and Cooling Turbo-cool 510 ATX power supply
Matrox Parhelia video card
Adaptec SCSI card 29320LP
Seagate Cheetah 36.7GB SCSI drive ST336753LW
2 Seagate Cheetah 18.4GB SCSI drives ST318453LW
Asus DRW-0402P DVD-R / RW Drive
Generic diskette drive
1 Viewsonic 19" VX900 LCD display
2 Viewsonic 19” VP930B LCD displays
Western Digital WD2000JBRT drive
Big case with lotsa fans

 

[wahnula]

Why did this happen?

Possibly brown power (<120 volts). Or not. You must surrender yourself to the mystery...

Any ideas about what to do next?

Yes. Strip down the system to PSU, CPU, 1 stick RAM only. No HDD, no peripherals, just the basics w/ video & wired PS/2 keyboard & mouse. See if it POSTs. Next step would be to try a known good PSU, they are cheap and it is good to have a working spare. Let us know how this test goes, best of luck!

Tony

 

[stumpinator3]

> Possibly brown power (<120 volts).

Yeah, I debated mentioning it -- and didn't -- but that seems to be the case. During the outage I was sitting in the kitchen, and there was a faint humming. Took me a while to realize that shouldn't be. Came from a portable cassette player that runs off AC or batt. Someone had left a cassette in there, on play, and it was at the end. No batteries in there, so I unplugged it, noise stopped.

But why should a brownout harm the computer? The UPS had kicked in just fine, seemingly. It's not just spikes that cause harm?

 

[maultier]

There's a somewhat common misconception that a battery backup unit is a ups. UPS's do power conditioning. BBU's do not. A brownout could indeed affect your system even if a BBU is attached.

 

[wahnula]

UPS's do power conditioning.

Not all do, you need to seek one out with that feature... called Automatic Voltage Regulation or the like. Smart UPS's will shut your PC down unattended. You will also have a log of all power-related events, so you can take advantage of their $100,000,000 connected equipment warranty

The UPS utility should also have thresholds you can set to determine at what voltage the battery should replace wall power (too much or too little voltage). I prefer Cyberpower's utility to APC's PowerChute.

Tony

 

[maultier]

As you can see the lines are very blurred. When you're taking about home units, the terms have become interchangeable. The bottom line is that if you are not going thru conditioning circuitry that keeps steady power to the system, then your protection against surges and sags is very questionable.