Bad computer

Factual Questions
1

Any technical people in here? Here’s a challenge.

My computer’s broken.

It’s two months old, but it doesn’t have a warranty since I built it from parts.

Basically, it boots for a minute or two and then it powers down. After that, it powers down two or three seconds after I turn it on, or it keeps cycling off and on.

This only happened after my power went off one night in this part of the house. But don’t consider that too much because I don’t want to accidentally connect two completely separate events. The computer booted fine after the power went back on, but six hours later, it shut down while I was working on it. Since I run Linux, this was alarming. After the blackout, my computer exhibited the behaviour I mentioned before. When I turned off the power at the power supply for a minute, it started working fine. Ten hours later, it powered down again and hasn’t been able to boot since.

My first reaction was to change the power supply, which I did, but the problem persisted. I don’t have another computer with which I can swap parts. I’ve tried unplugging everything, leaving just the power supply, the motherboard, a video card, and a hard drive for load, but I have the same problem. I’ve also tried using one memory module at a time, since I have two modules.

The motherboard’s an Asus P2-99, and the chip’s a Celeron 500. It’s mounted on a card thingy that plugs into the Slot 1, and there’s a working fan on the CPU. Other components are: two Western Digital hard drives (a 13 gig one and an old 1.6 gig drive), an ATI Xpert 98 video card, Soundblaster PCI128, 256 megs PC100 RAM, AOpen modem, floppy, CDROM, and a NE2000 clone.

Other observations: once when it booted far enough for something to display on the screen, it said something about the CMOS being corrupted; it had failed a checksum test.

Also, my motherboard’s not grounded to the case with a grounding screw, if that’s a problem at all; it’s just mounted on plastic all around. It was the first time I’d built a computer, so I’m considering the points where I might have screwed up.

I’m about to run out and buy another motherboard, but that’s kinda expensive and I’m wondering what options I have. What are the chances that the processor is busted? The problem seems vaguely like overheating, except a normal Celeron shouldn’t overheat that easily.

The last thing I was doing was reading USENET and listening to Tom Waits. I hadn’t touched the insides of my computer for a month before the incident, although I flashed the BIOS about two weeks ago.

Could I have inadvertantly introduced a short circuit somewhere? How can I find if and where?

That’s all I can think of now. I’ll post more information when I think of it, or if I experiment further. But I’ve hacking away at this problem for a few days, and I have projects looming up ahead, so I’m trying to get this fixed as soon as possible.

2

I’ve been working with hardware most of my life and in all my years of experience I can say that I have had a lot of success with a good kick right to the case!

3

Ugh, it’s getting worse. I tried booting from a floppy and using ext2tools in DOS to copy over some essential files, and it told me the disk partitioning is corrupted. Ugh, I say.

4

hey Xekul,

if you got a message about your cmos being corrupted it just might be, without your BIOS working, well, nothing works since that’s got to boot first. Sounds like its not.
I’ve never heard of anyone replacing just the BIOS/CMOS anymore, but it is possible. Did you build the motherboard yourself? If so, only you can find the short if there is one i suppose (easily anyway). I’ll see what i can find…

hope you have some luck soon.

5

Thanks for the replies.

TrayJay: I would, but… but, it’s my baby :stuck_out_tongue:

soul: I didn’t build the motherboard… I’m not that competent :slight_smile:

I’ll further explain the CMOS corruption message: when that came up, it said it set the settings to the defaults, and then it brought up the BIOS setup. I saved and exited, and I haven’t seen the message since…

6

Are you sure that it’s not a problem with the power outlet? A fuse, perhaps?

Other than that, the only suggestion that I can make is to try putting in an old (but functional) board, just for testing purposes.

Good luck!

-David

7

Call the place you bought the MB from and bitch. Tell them it never worked right and you want a new one. If it does the same thing then you know it isn’t the MB. Continue to do the same with every major element until the manager comes over to kick you in the head.

8

I’ve tried a different outlet, and I’ve tried plugging it into the socket without a surge protector…

I don’t have any other ATX boards to swap with…

I’d start exchanging the parts back to the store, but it’s been almost two months since I had the computer, and the warranty only goes for 30 days…

9

I’ve had computers with bad CPUs, bad motherboards, bad hard drives, bad modems, and bad power supplies. None of them acted like your machine.

When if powers down, is it really the computer powering down or is it just the display going off?

Did you review the BIOS settings with your motherboard manual in hand? The default settings may not be the ones you need.

Is it possible that there are some energy saving settings in the BIOS that might have been accidentally set put the machine to sleep after 30 seconds of no keyboard activity?

How does the computer do running DOS? Does it power off when it is in DOS?

Which hard drive do you boot from? The WD 13 MB? Have you been able to (a) fix the partition problem, (2) check the disk for errors and for bad sectors.

10

Yeah:

It actually powers down; the power supply fan stops running. I’ve tried changing the BIOS settings to what I had before. I disabled all the energy stuff in the BIOS, but it doesn’t shut down after 30 seconds; it shuts down after a minute if I left the computer off for a few hours, and it shuts down after a few seconds if it had been on recently. This weirdness made me think it was overheating, but I don’t see where that could happen.

It doesn’t work in DOS, either, when I boot from a floppy. But usually it doesn’t have time to get to the operating system before it shuts down.

I’ve tried booting from both hard drives. The partitioning problem might be a quirk with ext2tools, like, say, if the ext2 filesystem was revised recently, because I can read the partition from Linux. I actually had an uptime today long enough to copy some notes to a floppy. Linux does a fsck (filesystem check) on bootup if it wasn’t shut down properly, but this takes several minutes and my computer keeps shutting down in the middle of the procedure. This can’t be good for the filesystem, so I’m avoiding booting the operating system for now.

11

Just about anything could have been damaged by the power outage (I build computers for a living, and I’ve seen enough burned out this way…), but it sounds to me, most likely, like a bad power supply. This makes sense because it’s directly connected to the high-voltage power and in an ATX system is perfectly capable of shutting down your computer all on its own. My second vote would go to the motherboard, since this is the other half of the power down equation (notice that your power button connects directly to the motherboard). The CMOS checksum error is likely due to a weak BIOS battery on the motherboard, or perhaps the CMOS got erased or corrupted by stray voltage - this could cause the trouble too, in which case you need a new motherboard.

However, any part which got burned by the juice could be causing the mainboard or PS to detect an overload and shut down on its own. Or the CPU or memory could be having an error and occasionally executing the instcructions necessary for turning the power off.

I would start the diagnosis by stripping your computer down to the essentials: just a floppy drive, keyboard, and video card, with no hard drives or other peripherals attached. Meanwhile put the hard drive in a good computer temporarily and see what you can extract from it. Boot this way from a floppy and see what happens - if it persists, it’s definitely the motherboard or PS (and less likely, maybe the CPU, memory, floppy drive, or video card). Assuming it still gives you trouble, see if you can put the CPU, memory, drive, and video card in other computers and see if they work OK - if they don’t, return them. If they do, since your stuff is only 2 months old, you’re still in range of even the shortest manufacturer’s warranties on the power supply and motherboard, so call them real quick, because it’s one of those two items.

If it does boot OK with just the bare essentials, gradually add stuff back until the problem occurs again. Whatever the most recent part you added is, that’s the most likely culprit for the trouble and it should be returned to the manufacturer.

As a side note, blackouts are often preceded or followed by surges and/or brownouts, and most surge protectors just don’t cut it. Get yourself a good uninterruptable power supply, with voltage monitoring and noise filtering (I recommend APCC’s Back-UPS Pro series, preferably in the 650VA range). I speak from experience, it’s worth it.

12

Oh, as a side note, I forgot to mention:

Your computer DOES have a warranty, most likely, it’s just offered by the manufacturer, on the individual parts. Motherboards typically have a year, CPUs 3 years, memory is lifetime, power supplies are usually 90 days. If the store won’t take the stuff back, they may at least be able to hook you up with the manufacturer’s warranty replacement phone number. I build from parts and return stuff all the time…it’s relatively easy, though you do have to pay shipping to the manufacturer (they pay shipping from them to you).

13

Being you can get a new board on the net for maybe $40.00 with chip, that’s what I would do first. You simply cooked it, that’s it.

On the other hand, since I have seen so many computer questions in General Questions, wouldn’t they be better suited for the MP forum?

14

Thanks to everyone who replied. I think I have my problem fixed.

I don’t know if I should believe it myself, or just cross my fingers and knock on wood.

Before I headed out to the store tonight, I realized there was one component I hadn’t checked or replaced, and to amuse myself, I dug out another power cable and plugged it in.

Then I turned it on, booted Linux with root mounted read only, and waited. Seeing no evil, I rebooted and went the whole way: it checked all three filesystems, and now it’s sitting there at the login screen.

It’s been up for half an hour, but I’m afraid to touch it out of fear of ruining my luck. I realize that the uptime is proportional to the downtime, but it hadn’t stayed up nearly this long before.

But it was a power cable. A freakin power cable.

t’s the little things you have to watch out for.

15

Doh!
Xek, I should have thought of that with the symptoms you described. Good call!

I am glad you got it up and running.
Welcome to the head knocking world of tech support. :slight_smile:

pat

16

I don’t see how it can be the power cable at all. Anyway, one trick with ANY appliance, computer, vcr, tv, etc is to unplug it from wall for at least a minute & then plug it back in. This gets tons of stuff going again. Maybe thats what you did?

17

Well, I’m embarassed. If I had remembered what they taught me about troubleshooting in customer engineering school at Itty Bitty Machines 30 years ago I would have suggested checking the power cable.

In addition to bad CPUs, hard drives, mother boards, modems, and keyboards, I did once have a bad power cable. But it was easy to diagnose. The first time I plugged it in it went poof and tripped half the circuit breakers in the house.

Congratulations.