Computer shuts down by itself

[ijijijij]

hi

my desktop computer has been shutting down by itself recently. it just shuts off as if the power has gone out, i mean there is no shutdown process or anything. the computer just abruptly turns off. then i have to put in on different outlet etc. to make it work. but again then on the other power outlet same problem occurs. so i dont think thats its power outlet problem. the computer is in alienware case with proper cooling system. and i suspect that its not either the heat problem as the computer even shuts down even when its just been turned on after a long gap. i dont think that its harddrive problem as i have recently formatted the harddrive and there are no viruses, etc. also, first the compueter used to shut down after long time periods but no the time gap has become smaller. now it shuts down even within few seconds. i have cleaned the computer from inside, still its the same problem. now it narrows down to either ram problem or hard drive problem or heatsink problem. could there be any other reasons for this? i will try to check for faulty ram and hard drive. if that doesnt work then i will try replacing the heatsink. or should i check the connections of heatsink too? if they are properly connected. i am not too sure about the heatsink connections.
any help would be greatly appericiated thanks!

computer config: about 1 gb of ram , 1.8 ghz processor, pentium 4 and 40 gb hard drive space. the ram is is not installed exactly as 1 gb, its on three slots, windows xp

 

[Jase123]

This could be a shorting motherboard. Take the motherboard out the case and put it on an anti-static bag. Then try to boot.

Check your memory with this memtest. There is also a tutorial on how to do it there.

Regards Jase

 

[AlbertLionheart]

It might also be a problem with the power supply unit. Check that the fan is spinning and hold your hand in the airflow coming out of the back - it should not be hot.

 

[ijijijij]

thanks for the replies!

yea i will try to check the motherboard.

the fan is spinning so i pressume thats not the problem

thanks again!

 

[AlbertLionheart]

If the PSU fan is spinning it might still be that the PSU is getting too hot if the thing is full of dust bunnies. If you take the lid off, disconnect it from the mains and be very very careful not to touch anything inside. The capacitors in there can carry enough current to kill.

 

[Spyder_1386]

hey there.... i used to have a similar problem. Mine would switch off the moment i put a cd into the cd-rom and the cd starts spinning. It was a power supply problem. i would suggest u upgrade your power supply or replace it.

PS. Take it in and check if its faulty first...

Spyder_1386

 

[ijijijij]

update

hi guys!
I checked for ram and hard drive and both seems to be fine.
i was able to gather some more info about my computer regarding this problem.

cpu temp: 50 C
M/B temp: 32 C
cpu fan speed: 5000rpm
chassis fan speed: N/A

V(core): 1.690V
+3.30V 3.274V
+5.00V 4.780V
+12.00V 12.903V

some bios settings:

suspend to RAM (S3): Auto
Return on AC/Power loss: Power off
Ring-in Power on: Enable
S.M.A.R.T. for hard disk disabled.

I have also got few photos of the computer. here they are...


1) pic of psu (one screw is missing...so its not too tight)..dont know if that could be the problem

http://img218.imageshack.us/my.php?image=dsc1159et5.jpg


2) pic of front on the computer (the top one is the power button...i dont know whats the bottom buttom the one which is highlighted)

http://img218.imageshack.us/my.php?image=dsc1164gq9.jpg

3) a wire coming out of heatsink..maybe its supposed to go somewhere or maybe its just a spare one.

http://img218.imageshack.us/my.php?image=dsc1139nh1.jpg

http://img216.imageshack.us/my.php?image=dsc1140lw1.jpg

hope thats some help.

thanks everyone for yr quick replys

 

[mailpup]

From picture #1 I notice the power supply is installed upside down. That is why the screw holes don't line up. And because it is installed upside down, the power supply is not being vented or cooled properly. There might even be a second fan which should be at the bottom but is now ineffective at the top. I'm not saying this is the solution to your problem but it isn't helping matters much.

The button in picture #2 appears to be the reset button. When pressed it will restart the PC. You only want to use it if your PC is frozen and won't respond to normal shutdown or keyboard or mouse commands to do anything.

Also, I might be mistaken but it seems like you are calling your power supply a heatsink sometimes. The 4 pin connector in pictures #3 & 4 comes from the power supply not the heatsink. It appears to be the 12V ATX power connector. If your motherboard has the corresponding connector, it supplies power to the CPU and you must plug it in for the PC to operate properly.

 

[ijijijij]

worked

hi
thanks again everyone!

I cleaned cpu fan, psu, installed psu in correct position as it was insalled upside down. there were screws missing in few places including on the motherboard. so i installed some screws in those places. now the computer seems to be working fine! i ran it for 9-10 hrs and its still running without any interruption. first it used to shutdown very quickly but now its not happening. first i noticed that the cpu fan was running at about 4900 rpm but now it seems to be running at 5300 rpm. maybe thats what changed the situation. i have also installed additional hard disk and i want to upgrade to ram. i will ask about that in new thread. again, thanks everyone for your help!