PC shuts down randomly

I am having problems with my PC, for no reason it just shuts down. Not too frequently (about once a day) it just shuts down with no warning. After a shutdown, I can’t turn on my PC like I normally do by pushin the button in the front of the case. In order to turn it on again, first I have to turn off, and on the power switch button at the back of my case. Then I can turn on my normaly, and it works just fine, like nothing happened. I thought it could be either heat or power problem, and installed installed Asus Probe II, but it kept showing different things. First normal temperature, then warning…then again showed normal temp, and warning and so on…. Here’s the log, and screen:
===================================================
ASUS PC Probe II
Alert Log Report
Number = 27
===================================================
[10.25.2008 at 03:02 pm] +3.3 Voltage Abnormal, 1.67 V
[10.25.2008 at 03:02 pm] +5.0 Voltage Abnormal, 1.61 V
[10.25.2008 at 03:02 pm] Power Temperature Abnormal, 107 degrees centigrade
[10.25.2008 at 03:03 pm] Power Temperature become normal, 76 degrees centigrade
[10.25.2008 at 03:03 pm] Power Temperature Abnormal, 108 degrees centigrade
[10.25.2008 at 03:05 pm] Power Temperature become normal, 36 degrees centigrade
[10.25.2008 at 03:05 pm] Power Temperature Abnormal, 104 degrees centigrade
[10.25.2008 at 03:05 pm] Power Temperature become normal, 55 degrees centigrade
[10.25.2008 at 03:05 pm] Power Temperature Abnormal, 103 degrees centigrade
[10.25.2008 at 03:06 pm] Power Temperature become normal, 63 degrees centigrade
[10.25.2008 at 03:06 pm] Power Temperature Abnormal, 102 degrees centigrade
[10.25.2008 at 03:07 pm] Power Temperature become normal, 64 degrees centigrade
[10.25.2008 at 03:07 pm] Power Temperature Abnormal, 116 degrees centigrade
[10.25.2008 at 03:07 pm] Power Temperature become normal, 65 degrees centigrade
[10.25.2008 at 03:07 pm] Power Temperature Abnormal, 111 degrees centigrade
[10.25.2008 at 03:08 pm] Power Temperature become normal, 37 degrees centigrade
[10.25.2008 at 03:08 pm] Power Temperature Abnormal, 85 degrees centigrade
[10.25.2008 at 03:08 pm] Power Temperature become normal, 40 degrees centigrade
[10.25.2008 at 03:08 pm] Power Temperature Abnormal, 91 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature become normal, 38 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature Abnormal, 103 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature become normal, 65 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature Abnormal, 111 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature become normal, 34 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature Abnormal, 84 degrees centigrade
[10.25.2008 at 03:09 pm] Power Temperature become normal, 37 degrees centigrade

And my PC specs are:
Intel Pentium 3.2 GHZ with Freezer 7 pro cooling
2 GB of RAM
Asus P5GD1-pro motherboard
NVidia 8600 GT 512 DDR3
PSU Codegen 450 WATX 12V
Also have another Fan installed on the side of the case.
Please, can anybody help me solve this!!
Answer #1
what are you doing when it overheats? How long does it take before the pc shuts off? If your sitting there just browsing or so, reboot the pc and leave it at the BIOS>PC health status. See what overheats genreally. BTW did you try to clean out the HSF, Vid card etc?
Answer #2
I would say that you need a better Power Supply Unit.
Have a look at this thread:
http://www.google.com?t=1740332
I would say, the issue discussed here, is what is affecting your computer.
Answer #3
Try to clean the coolers
Answer #4
Well I am not doing anything in paticular when it shuts down. Once I was just looking a file in Microsoft Word, once looking some pictures….nothing heavy… And it shuts down instantly! First time it happened, I thought the power went out. Then I saw light on my monitor, and realized that the power in my apartment is okay but something is wrong with my PC…
My PC is 100% clean inside, and I have checked the case- fans are clean and all working, and I can’t feel the heat…looks ok. As for how long it takes before it shuts off….well I can’t say. For example, I have turned on my pc today 4 hours ago. It worked fine for 2 hours, and than it turned off. I turned it on again instantly and it has been working fine since (for another 2 hours…)…
Answer #5
serious PSU undervolt on the +5v and +3.3v lines. get yourself a more powerful PSU or unplug some stuff (eg hard drives you dont need, do you realy use your dvd drive?)
Answer #6
BUY a new psu! i had same problem
Answer #7
I think its the power supply jaro, uzmi novi
Answer #8
Well , use a better power supply , I got
Intel Pentium D(R) 3.00GHz
2GB DDR2 Asus nVIDIA GeForce 512MB DDR3
and power supply Delux ATX 600W P4 or something like that , and I have no problems
Answer #9
overheating, obviously…
open up the pc and clean it well, and try not to run too many commercial crap software that takes up 90% of your processor power for no reason, stick with light opensource stuff
Answer #10
overheating, obviously...
open up the pc and clean it well, and try not to run too many commercial crap software that takes up 90% of your processor power for no reason, stick with light opensource stuff
the 5v bus is running at 1.6v? how is that not a PSU issue?
Answer #11
I was suspicious about asus probe data, so I tried software called “aida” and here’s what It showed. This looks like normal voltage to me, does it??

Answer #12
that shows the system as more or less normal, which is weird. a complete list of your hardware would help (esp processor type, psu rateing, number of harddrives, and graphics card)
Answer #13
how is it picking up your power temp, don’t see that one much and that fluctuation in temp is nearly impossible for under 15-20 seconds, 111 to 37 to 85
anything very hot when it shuts down, very warm air coming out the PSU
this a pre-built PC ?
you check the BIOS (F1 to enter setup) power monitor settings
if nothing is getting warm or hot there may be a way to shut off power temp monitoring the power supply fan working & clean ? no obstructions ? 450 watt should be plenty for what you have