[SOLVED] Help! My computer turns off seconds after I turn it on!

No beeps or anything, if I flip the power switch that is actually on the power supply off and back on, it will fire up the fans (including mobo fans) for about 3 seconds, then turn off. No posting, no beeps, no hard drive whirs.

I pulled the power supply and hooked it up to the mobo on my spare computer and it ran for a minute or so just fine so I don't think it's the power supply.

My next course of action is to reseat the heat sink and see if that helps - my computer has one of those fancy digital temperature monitors but it has never worked right and will often beep to signal overheating after the computer has been on for a few minutes and then 2 minutes later go back to saying the chip is 80 degrees F. (I KNOW I don't have an overheat problem, my house is cold as crap and I have been able to do 3-d gaming for hours on end with no problems. I also have software that monitors temp and I am rarely above 85 degrees, I use my computer mostly for web surfing. However, there could be some internal safety mechanism preventing the booting in error? If reseating doesn't work I will probably just yank the whole thermometer and see if that helps.

Is it an HP?

No it's a custom built. I think it's 1.8 ghz, 1GB RAM, nVidia 6600GT, one hard drive, one dvd burner, 450w power supply. The mobo says "N1996" if that helps any.

Sorry then, can't help.

Good luck though. :)

I hate it when computers don't boot and there is no beep code. If it isn't the power supply my best guess would unfortunately either be a processor problem or a short in the mobo if you aren't getting anything at all, leaning towards the latter.

I would say 80-85 is pretty hot man...that's kinda the top end limit of temp for cpus as far as I know.
You could still be able to play games for hours at that temperature, I've done it myself by accident, but it does damage the processor quite a lot I think. If your cpu has been running near those temperatures for a long while my guess would be that the cpu is gone.

When you say it rarely reaches 85, what is it usually? Anything above 70 and I would start to worry.
Also having a cold house won't make a difference.
My quad core is running at 50-55 at the moment.

It either shuts itself down due to heat, the PSU is junk, or processor/motherboard need to be replaced.

I'm leaning towards your heat issue. Maybe clean off the processor and heatsink, and reapply some silver compound.

I don't think it is the heat issue alone making it not start. Heat is bad, and will eventually make the system not boot, but there's no way that it is getting up to 80+ and then turning off in three seconds. Of course, the heat probably did wreck something (either the processor or the mobo), but if they are heat wrecked there is probably no fixing them (unless you are some sort of electrical engineer, which I know you aren't).

If the PSU will power on another motherboard, but not yours there is likely a short somewhere. Try taking out or unplugging almost all of the componets except the RAM and CPU to see if you can get it to stay on, if it does, turn it off, add 1 item, and try again, do so until you add the thing that causes it to short out.

Quote:

---

Originally Posted by Rick Scarf

saying the chip is 80 degrees F.

---

Just saying.


PS, 80F = 26.67C.

Quote:

---

Originally Posted by wanabedriver

Just saying.


PS, 80F = 26.67C.

---

Lol, good point, I didn't even think twice.
I was talking/thinking in C, ignore my post.

Quote:

---

Originally Posted by ShitFace

Lol, good point, I didn't even think twice.
I was talking/thinking in C, ignore my post.

---

lol yeah I was wondering why it would be a problem for it to be running at just above room temperature

I did manage I think to maybe be on the path to eliminating the problem, I pulled everything off it and the little fan for the on-board video will continue to run past the usual 3 seconds, so I think the problem might actually be with a short in my fan/temp controller since that has never worked right anyway. I yanked that thing, but the problem now is that I've pulled everything off it is confusing as to where exactly things plug back into, they don't make motherboards like they used to and there are like 12 things that plug into jumper pins but I don't remember what goes where! I am pulling some manuals off the net, maybe that will help. I did figure out I have a MS-7125 v1 K8N Neo4 motherboard.

*****SOLVED*******

Posting this from my fixed computer, yay! Thanks for your help.

To others in a similar situation, my solution was to break down the motherboard into as small testable chunks as possible. I literally even took out the RAM and the plugged in video card. Every single wire connected to the motherboard other than fans was undone. (I had to look up a manual to get it back together, that was fun!! [not])

Anyway, by tearing down to that base I managed to get it to work, so I eliminated at least the whole board anyway as the problem, so I worked my way up from there. I plugged in the HDD LEDs, Reset Switch and Power Switch. It didn't work. I unplugged only the power switch from the jumpers and it worked. The power switch led to the problem. Apparently the button the front of my case had a metal part inside of it that had pushed in over time, I took the front of my case off, took out the decorative offending part, re-seated the power switch and tried it again. Success! I rebuilt the computer (took about an hour, I did not think to label stuff as I unplugged it) but it works great now!

On a side note I also yanked the temperature/fan speed monitor hardware, it has always annoyed me because it never worked and caused false alarms (I use AnVir Task Manager which is software that monitors CPU temp anyway) and covered that slot on the case with hot pink duct tape so now my computer has some street cred right?

Thanks again for the help.

Huh, wouldn't have guessed that. Glad you got your system working again.

Yeah that was kind of a weird one, I've had a lot of computer problems and this one was just a tad non-obvious. Moral of the story I guess is that it could be anything, so do a thorough process of elimination to isolate the problem. One nice thing about electricity is that is travels in a line so just start small and work your way up.

Sweet dude! That is definitely not a common/obvious problem, it sounded (as in my previous post) like a short, but I wouldn't have guessed that. Usually when there is a short, it is right after a build and people have a screw between the metal case and under the motherboard causing a short there. I would have guessed that one of your components was causing the short (like a drive or fan).

Oh that makes sense. I have a case which has a 'sticky' power button, which actually has the same symptoms. :shifty:

Congrats scarfy. Did queendork wonder what the hell you were doing?

Quote:

---

Originally Posted by Pepsi

Congrats scarfy. Did queendork wonder what the hell you were doing?

---

No she knows enough to leave me alone when I take the computer case apart because if she says anything to provoke me the beatings will go the other way for a change.

Quote:

---

Originally Posted by Rick Scarf

No she knows enough to leave me alone when I take the computer case apart because if she says anything to provoke me the beatings will go the other way for a change.

---

Wow. At least somebody will be touching your dick.


Wait, you meant....oh...sorry.