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Machine died whilst un-attended.

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February 25, 2006 1:52:08 PM

Thursday, my wife and I went to her mothers for the evening AGAIN, (this is a problem, but not the one I wish to discuss). When I left, both my machines were turned on and happily churning out BOINC wu's.

When we returned, endless hours later, one was dead. The normal light on the router which shows a machine is connected to a port was out, so I turned on the screen and there was the "No signal" message bouncing about. I think there was a light on the keyboard. There were no fans running on the box.

I pressed the start button and nothing happened. I pulled out the mains left it for a while, put it back in then tried again to start it. Briefly, (less then a second), the disk activity LED and the LED on the floppy drive flashed, but that was it, the power light did not light at all. There is no light on the keyboard. It is in the same state today after several restart attempts.

I put the system together from some old, some new parts last autumn. The MoBo, (ECS P4S5A-DX), CPU, (Intel Northwood 2.533GHz), RAM, (1x128MB 1x32MB), and ATI graphics card, (G-Force II MX-400), were previously in another case together and working fine.

Currently, these parts are in an older case, with a Seagate Barracuda, SMC LAN card, and Antec 400W PSU, (all new in the autumn), a CD-ROM from yet another machine, and the original floppy disk drive. The case has one additional fan installed. In neither machine has the CPU been overclocked, indeed, because of a misunderstanding with FSB values, for half of it's 3 year life, it was clocked at 1.9GHz.

The system has NT4 on it, and basically has just been running BOINC, (Predictor, Rosetta, LHC, SIMAP and Einstein), and has a backup Apache server system on it, although it has never been necessary to have it active. I have a hardware monitor running, and it has never shown any excessive temperature, typically max's out at 45C, well less then my other machine. The box is opened and the CPU fins and fan blades brushed and vacuumed every couple of months.

So my question is, what is wrong?

I can rule out enemy action as our apartment was empty at the time.

The brief flashes from the bootable devices imply the PSU is not totally dead, and why should it be, it is new, and well overated for the load.

I believe the PSU starts when told to do so by the MoBo, (as opposed to the start button connecting directly to the PSU), certainly the front panel switch connects to the MoBo, so presumably at least something is working on the MoBo.

The very quick shutoff suggests something seriously bad has happened somewhere.

Any ideas? (Sadly, I think what has happened may have happened even if I was at home, so "stop visiting your wifes mother", whilst having enormous appeal, may not work).
February 25, 2006 2:23:41 PM

When you put your nose in the case and sniff around, as well as smell the power supply, do you detect any acrid oder? If so, something may have burned out. See if you can detect anything like that. A power surge may have done some damage while you were away. Although if your other computer was OK then that theory may be a bit lame.

I would try clearing the BIOS. If that doesn't work, you're really in a situation where you need to swap out some parts to figure out what's gone bad. The power supply would be my first suspect. It's an Antec which is a very good brand, but I've lost a brand new Antec before in a puff of smoke!
February 25, 2006 2:24:09 PM

i think ur PSU is dead.
probably a surge in the electricity

edit: oops looks like we posted at the same time lol
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February 25, 2006 4:31:54 PM

Indeed, slaving in another ATX12V PS around the 300 watt range will likely cure your systems behavior; PSUs do go bad with startling regularity, moreso than do processors or mainboards!
February 25, 2006 5:52:02 PM

I remember a Compaq Server that I had for lab testing blew it's PS on me. Scared the living crap out of me too.

Then the smell came around.. Man, I was thinking at the time, I hope that is only the PS I smell .. hehe

Had to call it in for RMA.. That was 6 years ago.. I can still remember that certain poppin noise it made.. :lol: 
February 25, 2006 6:38:44 PM

oh yeah speaking of which...

i blew a PSU for no reason whatsoever

the thing about it is its on the same line as my two other PCs

so its not that strange really, to see one blowing and the others in perfect working condition
February 28, 2006 10:38:57 AM

Today, I had some time to play with the machine.

First, there was no smell, either originally or now. I am familiar with the smell of burning elctronics I'm afraid! If there had have been an event while I was out, it is well possible it would have cleared before I got home, there are other machines in the area and considerable air movement.

The first thing I did was take the cover off and try again. Both the fan on the PSU and the CPU fan started spinning but stopped again almost at once. Otherwise, the machine was the same as before.

I took the Antec out and put an old 300W Sparkle in. I knew this PSU to be working when I took it out of the same machine in October - the reason I'd put the new Antec in was because I thought the higher spec board, processor and hard disk may be a bit much for the old, and quite noisy Sparkle.

Anyway, turning it on, with just the MoBo powered, the same thing, the fans twitched but nothing ran.

I have now removed the data cables from all the disks, (Seagate 120GB, Hitatchi x56 CD-ROM and the "floppy" which is actually an LS-120), pulled out the video card, the network card and the RAM stick.

With just the MoBo, CPU/heatsink and front panel switches connected it is still doing nothing, fans twitch but thats it. The behaviour is the same with both the Antec and the Sparkle.
February 28, 2006 11:03:03 AM

Looks like a fried mobo, it if doesn't start beeping madly due to the lack of RAM and vidcard. Sometime's electronics just go poof for no good reason...

Bummer. At least old mobos like that are really cheap on eBay. Might be able to pick up a whole system with a similar mobo for dirt cheap for extra parts.
February 28, 2006 12:22:21 PM

I hope I don't sound crazy but this recently happened to me:

Similar issues, I would try to turn the comptuer on, and it would shut off right away. What was wrong with the Dell Optiplex 620?

BAD POWER SWITCH!

Never heard of that before, but the bad power switch was shutting the computer off every time I turned it on. I told Dell I thought it was the power switch after replacing the power supply, but Dell insisted that I replace the motherboard, RAM, CPU, and ANOTHER power supply before they sent me the $2 front assembly. The computer was only a couple weeks old. (This isn't a rip on Dell, I like 'em!)
February 28, 2006 1:50:43 PM

Also check the 15-cent reset button if you got one hooked up.
February 28, 2006 2:02:47 PM

That's a bit of a weird one isn't it?

I'd have thought that a switch going bad would first manifest when trying to start or stop a machine, not whilst it was running? Same with the reset switch, (although I'm not sure I actually connected it in that box as I don't use it).
February 28, 2006 6:31:58 PM

Little bit more info, don't know if it helps. I put the Antec PSU back into the machine, and happened to leave the keyboard connected and have seen a little more then I have reported before.

If the PSU has been unplugged, OR if the PSU's own switch has been switched off, when switching it on or plugging it in BEFORE touching the front panel, 3 lights on the keyboard turn on then off. Once pressing the button on the front, the fans twitch then nothing. Having pressed the button once, pressing it again any number of times does nothing, no lights, no twitchy fans.

Unplug, or cycle the PSU's little switch and then again, the keyboard lights go up and down, then the first press of the button causes the fans to twitch.

The start button is not a latching button, it is a 2 wire momentary switch. To me, the fact that anything happens at all, (i.e. fans twitch), indicates it must be working.

I have also tried clearing the CMOS without any improvement.
March 1, 2006 5:33:23 PM

I guess I can rule out the PSU now. I put the Antec into this machine earlier today and it worked fine.

I guess also that it is now the MoBo or CPU.
March 1, 2006 6:03:47 PM

About the best you could hope for is that the on switch is sticking, to test that possibility just unplug the on switch and just quickly jump the two contacts on the board, if it runs its a sticky switch. By the way, with all those problems, I would start with a base post test with the major components, PSU, MB, CPU, RAM, Video, and nothing else. Now we would know its one of these items and youve checked the psu, so, its one of the other items, and never forget the power cord.
March 1, 2006 6:29:32 PM

My suggestion is do a visual inspection of the motherboard, you might have some blown capacitors. Also a bad powersupply could still give power, just not enough voltage. Best way is to first look at the capacitors and if all seems well there, swap out the powersupply and test again.
March 1, 2006 7:51:58 PM

The PSU from the dead machine was installed in this machine this evening as a test. This machine normally has a 450W Antec in it, it's a much more thirsty rig then the older setup, a hot Prescott, on a bigger Asus, with a lot more in the box. If the 400W can drive this, I think it could drive the older set up as it had been doing since October.

I intend to whip the MoBo out in the morning and have a look at it.
March 1, 2006 7:54:32 PM

I am already down to PSU, MoBo, CPU and heatsink. Nothing else in the box is connected, either power or data. I did try with the keyboard, the result was a little different, it is described further up somewhere.
March 1, 2006 9:44:20 PM

Just check all the capacitors on the motherboard, if its bulging up that means its blown and a new mb is needed. Also, try reseating the CPU, put some new thermal grease on because some motherboards will detect if the temperature is rising too fast, it will not let it boot. Hope that helps.
March 2, 2006 9:51:49 AM

Okay, so I have taken the board out of the box and had a really good look at it, nothing strikes me as odd. All the electrolytics look normal etc. Similarly, once cleaned of the old Arctic Silver, the processor looks fine.

Reseated, it behaves as before.

Questions.

1. Would trying to power on the MoBo without the CPU in place reveal anything? I'm thinking if the short is in the CPU, the PSU may stay running, but also the absence of the CPU may create a different fault which presents the same way without reealing anything.

2. Would trying all the +ve pins on the main power connector on the MoBo against a support screw with an AVO on resistance setting reveal a short on the MoBo, or is there enough stuff across all the rails to render such an operation pointless? Would doing something like that endanger the board if it was good?

3. If the CPU is damaged, can I risk damaging another machine/MoBo by swapping the potentially faulty CPU with the known good chip in the new host machine?

4. Opposite of 3 really, can I risk damaging a known good chip by placing it into the potentially faulty machine?

I do have a working machine, (this one), which has a 478 chip, but I really don't want to screw this machine up as well.
March 2, 2006 10:36:45 AM

Quote:
Okay, so I have taken the board out of the box and had a really good look at it, nothing strikes me as odd. All the electrolytics look normal etc. Similarly, once cleaned of the old Arctic Silver, the processor looks fine.

Reseated, it behaves as before.

Questions.

1. Would trying to power on the MoBo without the CPU in place reveal anything? I'm thinking if the short is in the CPU, the PSU may stay running, but also the absence of the CPU may create a different fault which presents the same way without reealing anything.

2. Would trying all the +ve pins on the main power connector on the MoBo against a support screw with an AVO on resistance setting reveal a short on the MoBo, or is there enough stuff across all the rails to render such an operation pointless? Would doing something like that endanger the board if it was good?

3. If the CPU is damaged, can I risk damaging another machine/MoBo by swapping the potentially faulty CPU with the known good chip in the new host machine?

4. Opposite of 3 really, can I risk damaging a known good chip by placing it into the potentially faulty machine?

I do have a working machine, (this one), which has a 478 chip, but I really don't want to screw this machine up as well.


I'm sure your Power Supply failed (what exactly caused it I cant say - spike maybe). :oops: 
When the Power Supply failed it may have taken the board, CPU and memory with it. :cry: 
I have seen Power Supplies spark - flames and nothing else damaged, and also seen nothing from a Power Supply fry everything. :roll:

You may want to take it into a shop and have them test the board and CPU. Most shops have that capability. :wink:
March 2, 2006 10:47:53 AM

As I said yesterday...
Quote:
The PSU from the dead machine was installed in this machine this evening as a test. This machine normally has a 450W Antec in it, it's a much more thirsty rig then the older setup, a hot Prescott, on a bigger Asus, with a lot more in the box. If the 400W can drive this, I think it could drive the older set up as it had been doing since October.
... the original Antec is fine, and a second known good Sparkle PSU did not help.

There are no shops around here, I have to get everything mail order unless I drive into Copenhagen, which is best avoided.
March 2, 2006 11:32:25 AM

The same thing happened to me. It just died suddenly for no reason while my other comp was fine.

The first indication you gave - fans would come on for a bit and then turn off would suggest a PSU problem. You said the 300W does work.... its been known sometimes the PSU will still power up a rig when there's not enough juice in it still but eventually it'll stop working. And besides, PSUs do die after a while also, like w/ any electronics. Eliminate the easiest possibility first. Put in that 450W and see if it works. If it still fails, then its not the PSU.

2nd indication - NO beeping sounds (considering you have the case speaker hooked up) , this is either the MB or CPU. Mine turned out to be the CPU (AMD XP 1500+ overclocked) that I had for 4 years that burned out. Swapping it out w/ my xp 2500+ fixed the problem. But this was only after I went out and bought a new MB already and when it still didnt work, I was stumped til I found out the curlprit was the cpu. From my experience, cpu's rarely ever die and mobos are much more fragile so I assumed it had to the mobo..........

My lesson? Always test out the easiest parts first before you do anything. Test out the memory 3rd before you do anything to the mobo.
March 2, 2006 12:49:09 PM

The 300W Sparkle does work, or at least it did when I took it out of the same box in October, it just doesn't alter the situation. The 400W Antec was installed in this machine, (a much bigger rig), yesterday and ran fine. I do not believe the problem to be with the PSU anymore.

As there is only the MoBo and CPU left, I guess it is one of these.

I don't think the "potentially faulty" MoBo will take a Prescott chip, so I can't put the chip from this machine in there. The only thing I have left is to try the "potentially faulty" Northwood in this machine, but I was wary of that in case doing so risked damage to this rig which I can't afford to loose. That is what prompted my questions above.

The system speaker is still attached - I was trying to get the minimum set up and have the "no memory" beep code. Nada.
March 2, 2006 1:43:07 PM

well it seems it as a fried mobo just trie and run it without anything connected to it and without any pci or agp just with the cpu to see if beeps, but those power surges can fried it up.
March 2, 2006 1:53:23 PM

Err, as stated above, several places now actually, there is only the PSU, the MoBo, the CPU and the front panel switches/LEDS left in the box.

The PSU is NOT dead, there are no spikes!
March 2, 2006 2:47:54 PM

Well it seems to me that after a little time and troubleshooting you have answered your own question. You've narrowed it down to the CPU or MoBo. Are either of those two parts still in a warranty by chance? If so send them in. Or if not, then your cheapest bet would be to find a cheap MoBo and swap it out and see if that fixes it, in hopes that you won't need to buy another CPU.

Just my two cents.
March 2, 2006 3:00:20 PM

Pull out the CPU and try turning it on again. If it powers up, then it's your CPU... if it doesn't, then it's most likely the motherboard. I'm more inclined to think at this point it is the mobo and not the CPU... but it could be both.
March 2, 2006 3:30:21 PM

Lan:

Since my last post, I have pulled the CPU out of this machine, and placed the "potentially faulty" CPU from the other machine in here. It ran. I stopped it at the BIOS screen, but everything looked fine, (I stopped it because the BIOS started saying "Hey new chip - let me change everything for you" type things which I didn't want).

I am sumising from this, that my CPU is still a CPU and not simply a stone/rock.

This leaves me with the MoBo or this sticky on/off switch business.

I'm urging away from the switch because the switch does seem to do something, whilst the MoBo does nothing.
March 2, 2006 3:38:05 PM

How long do the fans spin when you push the power button? a way to test the switch would be to swap the MoBo's cases, then try and run them both, and see what happens. Then you would isolate the switch and see if it is still a problem. Remember just because it does something doesn't mean the switch is working properly. I highly suggest checking it anyway, sometimes its only the simple things that we should check first.

Then, if it's not the switch, or the CPU it looks like you might have a fried MoBo. Try the case swap and post your results. I'm not really that busy at work today so I will probably be able to reply. :) 
March 2, 2006 3:38:55 PM

Zoron:

Out of curiosity, I did try to power the system up without the CPU and nothing happened. Is that really a suprise though, I mean, the BIOS needs a processor to run it, or does it have a small processor of it's own? I don't know.

Anyway, the CPU from the dead machine runs when installed in this machine.
March 2, 2006 3:41:36 PM

It will require a CPU to run, but not to power on. I was just curious to know if it would stay powered up without the CPU.
March 2, 2006 3:43:45 PM

hey, try this on your good machine. the next time you start it, instead of pushing and then letting go of the start button, push and hold the switch in, it should start to start, but since your holding the button in, it should be going through a 4 second count down to shut off, and in 4 seconds or so it should shut down
March 2, 2006 3:53:48 PM

Lan:

The Antec PSU's have 2 fans, a "puller" and a "pusher". The puller pulls air into the unit and is inside the case, the pusher exhausts warm air to the world - global warming. Normally the puller runs all the time, the pusher when the PSU internally detects heat problems. This arrangement keeps the noise levels down.

The "puller" is quite a hefty piece of kit. When pressing the button, it at most twitches, or turns maybe 1/4 round - never more.

When I had the older Sparkle PSU in there, the single fan started and stopped within a second.

The CPU fan is an altogether lighter affair, and varies between a "substantial twitch" to a "yee-ha" spin lasting perhaps a second, before chugging to a sighing halt. This could easily be capacitors holding enough charge to hold the rail up, or the generic lightness of the fan allowing a certain amount of variability.

Viz the switch, I can try pulling the leads off the head and shorting the pins with a bit of wire. I have yet to try this, but my wife is looking at 1) the dining room table covered with semi-disassembled machines, and 2) the steaming pot of chilli I am preparing, and making hungry "feed me" noises. This will have to wait until the morning.

I wish I had a job, a paying job I mean.
March 2, 2006 5:09:40 PM

Just attach your Mobo Power On/Off leads to the case's Reset Button instead of the Power Button. This will use the Reset Button as the Power On/Off button and will determine whether or not the actual Power On/Off button is the culprit (which I'm doubting).
March 2, 2006 5:14:10 PM

It is possible for a bad CPU to damage a Mobo, but unlikely.

If you pull CPU does the PSU fan come on on power up? (Don't know if that works, just looking for a way to test Mobo)

If that doesn't work I would try moving the proc to a spare PC (not the only other one you own, if you can help it. ) I have never put a bad part into a PC and damaged the new machine, but I suppose it is possible...

I've seen one fried CPU in my life, but several bad Mobo's so based on that, my money is on the Mobo. The one bad CPU behaved as you describe, only no power up or fan on at all. Two PSU's later, it was the proc.

If you have not eliminated the power switch daughterboard try jumping it. It would suck to wait a week getting a new Mobo or proc to find out the $3 switch was killing you.
March 2, 2006 5:23:20 PM

when I have proven to myself, the only part left is the motherboard, I unplug the power supply from the wall, then I push the start button to clear residual power from the machine, I pull the mother board battery and carefully jump the motherboard battery terminals. Then I replace the battery, plug the machine back in and try starting it. if it doesnt work now, it is the board "or possibly a dip switch or mostly off jumper. The nightmares are the intermittent problems. PS find someway to enjoy the time you spend, its a mental thing, Life Goes On!
March 2, 2006 7:05:16 PM

You might consider that you have a dead BIOS chip. If its dead, basically nothing will happen - which seems to be your case.

Even if the power is applied w/o the CPU, it should beep an error code at you (I'm about 90% sure on that).

In any case, after you fix it, you might want to think about what caused the motherboard to die. Otherwise it might happen again. Typically its a power issue that makes a motherboard fry. They're quite resilent.
March 2, 2006 7:11:20 PM

Quote:
Even if the power is applied w/o the CPU, it should beep an error code at you (I'm about 90% sure on that).
But what processor is running that program? I had always assumed the BIOS was simply an EAROM.
March 2, 2006 7:48:46 PM

I know there are beep codes for faulty CPUs. I assume that when it tries to use the CPU to launch the POST test, it can detect that the CPU is fried or broken, and then issue the error code. The first thing the POST does is check for power (heh) then check the CPU. If the CPU test fails, then it beeps.
If its not there... perhaps it won't, I'm not exactly sure.
March 2, 2006 9:27:36 PM

If the bios is working properly, it should beep, on hardware errors.

From the spreadsheet I did make on system beeps, a typical bios program should beep around 5 times, if it detects a faulty, or unseated (incorrectly installed) processor.
!