Random Shut Down

LSchaeffer

Junior Member
Sep 6, 2004
20
0
0
Hey all,
I am semi-new to the technical support end of anandtech, so forgive me if I am asking repeat questions. My friends computer has been having some major problems with his rig. He has a HP desktop.

The problem that is occuring is a random (in terms of time and position in boot up) shutdown/poweroff of the computer, EXEMPTING the power supply. What I mean by this is the computer will be booting up, and then all of the suddent the computer will "turn off" except, the power-supply doesn't turn off. To turn the power-supply off you have to hold the power button down until it turns off. I do not believe this is a software problem because I have tested the computer both booting normally, and booting from CD-ROM with a bootable linux (KNOPPIX). I also found a
Related Post

In the forums which many people stated the power supply was the problem. So I heeded this advice, and tested the computer with one of my spare powersupplies, but the problem continued with no change in frequency. So that rules out power supply. It's also not a HDD problem since it occurs with or without the hardrive attached.

At this point I am very lost with the problem and or solution to this dilemma. If anyone has any ideas as to what it could be, and how to fix it, it'd be appreciated. Thank you very much for your time.

Lance
 

VirtualLarry

No Lifer
Aug 25, 2001
56,570
10,200
126
I don't understand the description of your problem. Does the display suddenly go blank during boot-up?

Are you by any chance, using a motherboard that has integrated video, and you are also using a seperate video card?

Hmm, you said random. I wonder if somehow, a power-management sleep mode is kicking in? Can you disable APM and ACPI in the BIOS settings? (I'm not too familiar with current HP models, although OEM computers generally don't let you have full control over BIOS settings like white-box/own-built computers do.)

Is there a "sleep" button, either on the front-panel, or has a connector on the motherboard? Maybe a wire is frayed or touching something somewhere.

It would be easier to attempt to diagnose if you could provide a slightly more-detailed description of the problem, including exactly what happens when it does whatever it is doing.

 

L1FE

Senior member
Dec 23, 2003
545
0
71
Are you getting any beep codes? Like VirtualLarry said without more specific information it would be difficult to diagnose the exact problem.
 

Turkish

Lifer
May 26, 2003
15,547
1
81
If it's not th ePSU, I'd guess it may have something to do with the MOBO. Or you may try tracing the wire for the sleep mode and see if you see anything there. I'm guessing it has something to do with the MOBO but need more specific information. Can you get to Windows at all? Does this happen when you're in Windows or just when you're trying to boot up and you get to Windows after a couple tries? Really really need more info on the sequence of events.

:wine:
 

LSchaeffer

Junior Member
Sep 6, 2004
20
0
0
Alright guys, thank you for your responses, I will do my best to describe the problem better.
When I say random, I mean that it has occurred at different points in the boot routine. for example.
The first time it happened, he was on the computer, up and running in windows. Suddenly, what seems to be the computer just "turning off" occurs. When I say "Turning off", I mean the signal to video drops (monitor says no-signal), the CPU fan stops spinning (so I'm assuming the CPU is also disabling itself at this point, could be wrong), and all the HDD and CDROMS stop spinning (if they were currently being used). However, the powersupply was still on (fan spinning), and the small power LED in the front of the case still showed the case getting power.
When I went over to diagnose, I then began attempting to boot the computer up. At this point, the computer would repeat the symptoms above, but this time at different intervals of time up to windows starting up. Usually i would get to the screen with the windows logo and the bar panning the bottom. At this point, I assumed maybe he just had a corrupt file or two, or some virus that was messing with him, since it seemed to be consistently during the startup. I could also not bring it up into safe mode, as the same problem occured.
However, one time, it actually let me boot up into windows (in safe mode). (this was probably the 4th or 5th try of just turning it on and hoping for the best). At this point, I did a system recovery (wiped everything, formatted, and began anew). And it seemed to boot up fine. Then I shut down, and tried to turn it back on, and the problem continued (same symptoms above, with no specific location during boot sequence to make it seem like one component or another was causing the problem). At this point, I thought maybe the HDD could be bad, and it was causing some problem in the boot sequence I couldn't identify, and so I used a bootable linux CD to boot from CDROM, and completely unplugged the HDD. However, doing this, the same symptoms described above occurred. Then I thought it might be the PSU, so I took one of my spare PSU's that was functioning properly and hooked it up to his system. However, after I made this switch, the symptoms were still exactly the same.

I hope that describes the actual problem a little bit more in detail. In response to the questions above...
I am using a motherboard with integrated video, however, there is not also an attached video card.
During this process, I received no beep codes indicating that there was a "problem" in the boot sequence persay either.
The problem occured when I was in windows, when I was booting to windows, and when I wasn't involved with windows at all (happened while I was in BIOS a few times)
I am not sure about the APM and ACPI settings in BIOS, I will look around BIOS to see if I can change them. However, he did have a very limited BIOS when I was poking around, so that might not be possible, I will repost when I can look into that.
As far as a "sleep" button, I do not believe his computer has a sleep button on the case, but there might be something on the motherboard that is a self-initiate sleep or something, that could be shorting. I will have to check the specs of his PC to figure out his exact MOBO (I will also post those specs when I get them, I can't remmeber his exact model right now).