We had an intermittent power failure last night.

I woke up this morning and wandered into the kitchen, and saw that, in place of the time, the LED on the microwave was displaying a "PF." Most of the clocks have battery backups, but the one in our antique (sixties era) electric stove was about an hour behind.

Computers had to be restarted, natch.

After doing so, I was using my desktop (my primary work machine) for about a half an hour (the one in which I'd recently replaced the motherboard), when it decided to reboot itself, seemingly spontaneously.

Then, after the reboot, right after login, and the desktop coming up, it did so again.

After repeating this two or three times, it bluescreened. This was similar to the symptoms before I replaced the mobo the last time. Except that this time, after finishing writing whatever cryptic diagnostics it was sending to that future, in which the technology might exist to revive it, it didn't reboot--it just shut down.

And wouldn't restart. Poking the power button was availless.

So, now I've got to figure out what's wrong with the thing now. I may have a power supply problem, but I may also just need to upgrade to a better board.

Anyway, I'll be working on the laptop for the nonce.

[Late afternoon update]

Dang.

I was hoping that it was the power supply, but I just tried another one, with the same result. The power switch is fine, based on a test with an ohm-meter, and shorting the terminals on the motherboard doesn't give any action, either.

I still need to verify that the supply I swapped is good, but it looks like there's a problem with the mobo. I just bought it about a month ago, and it's probably on warranty, but I only paid thirty-some bucks for it, so it may be best to simply upgrade and get a more modern one.

Oh, as for the suggestion in comments to unplug everything from the board except the video card? That's already my configuration. Everything else (sound, ethernet, etc.) is built into the board.

Rand,

Is the laptop using Windows XP? Did you recently install Service Pack 2? I, and several friends/acquaintences, have had or heard of others having this same problem. Restore tyour XP installation by booting from the XP install disk. Back up all information from the laptop, re-format and then re-install both XP and SP2, and all should be well. Or you can just run without SP2, thought it does have some improvements.

Cheers!

Here's a related article:

http://www.crn.com/sections/breakingnews/breakingnews.jhtml?articleId=23905071

A question from a bonehead, if I may: Since the BSOD and subsequent refusal to power up, have you tried removing the power cord from the computer-end connection (the reverse plug)?

My PC has occasionally refused to power up after a PF, and unplugging and re-plugging that end of the cord has always worked in that instance.

If it doesn't work, just remember: I am a real, honest-to-goodness bonehead. Don't try this at home.

McGehee,

I've had that problem as well after "involuntary" computer shut-downs as well. I have only guesses as to why this occurs.

On further reflection, let me add that this was on a desktop system, so I wonder if having battery power thows a monkey wrench in the equation. In any case, the boot/fail/reboot cycle (all without any user input!) seems to be an XP SP2 issue.

My laptop is running Windows 2000, though I'm not sure why you're asking, since I'm having no problems with my laptop. It's the desktop that died (which is also running Windows 2000).

And yes, I did try unplugging and replugging the power cord. No joy.

I'm wondering if I've had a flaky power supply all along (though I did have to replace the other mobo after I broke the memory slot on it).

Rand,

Sorry - I mis-read. Early morning eyes combined with a foggy brain.

Rand, I had a computer do something similar a while back, pre-SP 2. I could push the power button and the power light would come on and the disks would spin up, but the machine wouldn't POST. Is this what you are talking about?

Just for the heck of it, take 5 minutes and pull the CMOS battery and then put it back. I did that and the computer has worked fine ever since (been about 16 months so far.)

Back in the days of Macintosh clones (remember the good ol' days?), I had problems with one of my clones, symptomatically motherboard-related. Three mobos later, the power supply was replaced, and all was right with the world.

I wouldn't be overly surprised if it was the power supply. A flaky PS in a computer is as frustrating as a flaky battery/alternator in a car.

When purchasing a new PS, don't be sucked in by claims of high wattages. Be sure to check the amp ratings on the 12V and 5V rails and look to see how many plugs you get standard off the wiring. A low-end 450W PS will be less reliable than a higher-end 300W PS.

Again, like last time, Newegg.com is a good place to look for this sort of thing.

No, there's no power at all. I hit the power button and nada happens.

Quote: "My PC has occasionally refused to power up after a PF, and unplugging and re-plugging that end of the cord has always worked in that instance."

When your computer fails to power down, just hold down the power button for 10 seconds and it will eventually power itself off.

Same can possibly be true for a system that refuses to power up. Hold the power button down for at least ten seconds then let off for ten seconds and then try to press it again and see if it comes up.

CMOS clear could help. Also the standard next practice : remove everything except the graphics card and a single DIMM from mobo, leaving case connectors and power on of course and try power then.

Don't overlook the power switch!

Also, I don't think you can assume the power switch is necessarily just a plain switch. It may interact with various interlocks, fan leads, mobo connects to CPU temp sensors, etc. To test the power supply you may need to pull it out and just apply a meter to it.

But, yeah, obviously you are having a hardware problem, and this has nothing whatsoever to do with your OS. The system is failing before the OS is even booted.

Step 1 is probably the simple task of opening up the case and wiggling each connection, making sure they are tight, and poking at the wire harness, seeing if that triggers weirdness. Since you just replaced the mobo, you probably bumped and fiddled with a lot of stuff. You may have had a tenuous connection that was hanging on just so long as it didn't get bumped, and now it's on the fritz. If it's because some cable end was never properly seated, you can firm it up and win. If on the other hand some wire was 98% severed and is 100%, you can replace it.

Anyway, as a general thing, don't forget the wires and interconnects. They are just as important as the big components, and a whole lot cheaper to replace. Also, since their technology is still essentially of the 1960s, it isn't quite as reliable.

Quick and simple test #1: If there is no LED lit up on the NIC (with the switch on the PS flipped on), there's no power to the mobo.

Quick and less simple test #2: Take a multimeter, set on DC, and test one of the leads off the PS with the PS turned on. If there's no juice, there's no juice. All of the jiggling, wiggling, pushing, and pulling in the world isn't going to change that.

It's not too tough to fry a power supply, really. And if the PS is decent, it should blow up before it fries something internally. They make a really really loud "pop" when you hook them up to 220 instead of 110, too...

Start with the most straightforward tests; check for power from the PS. After that, fiddle with switches, cables, etc. To do it in reverse would be terribly inefficient, IMHO.

I had a similar issue. I reflashed my ROM BIOS on my less than a week old mobo, reset, checked BIOS settings, everything seemed to be fine. Everything was fine until I powered down, whereupon no pushing of any switch (actually any key on the keyboard was how I had it set in the BIOS) would make it power on. I tested the power supply (fairly new), and it was good. I new I was getting some power because some LEDs on the mobo would light up.

I reset the CMOS, whereupon, it booted just fine. Of course, I had to then go through every bit of the BIOS to get it set up to what I wanted, but it did come back.

Rand: It's the desktop that died (which is also running Windows 2000).

And for the record, my PC also runs W2K. Too bad my suggestion didn't work.

When your computer fails to power down, just hold down the power button for 10 seconds and it will eventually power itself off. ... Same can possibly be true for a system that refuses to power up. Hold the power button down for at least ten seconds then let off for ten seconds and then try to press it again and see if it comes up.

Thanks, Hefty -- next time that happens to me, I'll try it.

quote: "It's not too tough to fry a power supply, really. And if the PS is decent, it should blow up before it fries something internally."

I dunno it is not that uncommon for a power supply to take out a few other hardware components when it goes bad.

Matter of fact my mom is wrestling with Dell support right now because her power supply went south and took what they thought was the video card with it. I told her though to make them replace the mobo when they replaced the video card. Of course the technician that come out only replaced the video card and left the mobo as is. then, left before running her system restore disk. She had to reload windows cause of yet another indication that the motherboard has a problem because her original windows install wouldn't boot properly complaining about the windows kernel not loading. Upon reloading her windows xp disk the setup unexpectedly reboots everytime it says it is optimizing the display settings. I told her to call them back, and insist that the mother board be replaced as originally stated.