System abruptly shuts down

Hi,

I have been banging my head to solve an issue that I have with my system. It turns off abruptly and the keyboard lights remain on. there is no time frame to it. I suspected cpu over heating and have installed 2 extra fans, have tried using the system with the chasis open but still it shuts down. once shutdown the power button or the restart button does nothing, have to cut the power and then restart. Have gone thru the event logs but there is nothing in it except ' previous system shutdown at xxxxx was unexpected'
Below are some details about the system.
Pls help.

Vista ultimate 32 bit SP1
P4 3.2 GHz, 800 MHz
512 mb x 2, 533 MHz RAM
Intel D945GCNL board
ATI Radeon x1650 256 mb PCIe video card
250 GB x 3 Seagate HDD
Viewsonic 19 inch TFT monitor

 

Are you sure it's a hardware problem and not a driver/BIOS problem?

 

Boot into Bios and let it run in the Bios. If it shuts down in Bios you know you have a hardware issue. Let us know what happens. Jazz

 

Thanks for the replies. I have kept the system on at the bios screen for a night and it did not turn off. Under HW monitoring in bios I notice that the cpu temp is 75 plus most of the time even after having 2 extra fans in the system. could this be the problem? I even took out the system hdd and used in a different system ( D915GAV board, P4 3.4 GHz, 1 GB x 2 DDR1 RAM) and the system was working fine. kept it on for 5-6 hrs without any issues. this makes me feel it could be something related to HW .. or bios as EnfoToad mentioned.

 

It is running hot. Your running Vista on a Pent 4 I see. The memory is awfully low for the the graphics required in that OS. Is Vista relatively new to your System, (i.e., upgrade?). If you were running XP previously was there an issue.
The video in Vista requires a lot of memory and power and it may be your overloading the systems capabilities. It would run in Bios fine in that situation because Bios isn't running the graphics level Vista would pull.
What PSU are you using? Let us know...Jazz

 

this needs to be addressed.........maybe a reapplication of thermal compound

 

If you are saying 75c then that is the issue and I would double check that the hsf is down tight with all 4 screws in (which is really hard to tell without taking the board out incidentally) and if it is I would say it needs replacement.

 

I have been using vista for a year now. It was a D915GAV board, P4 3.4 GHz, 1 GB DDR1 RAM, 128 mb nvidia 6200 tc video card earlier. this system was built about 3 mths back with P4 3.2 GHz, 800 MHz, 512 mb x 2, 533 MHz RAM, Intel D945GCNL board, ATI Radeon x1650 256 mb PCIe video card, 250 GB x 3 Seagate HDD. the PSU is generic 450 watts one.

 

Missed the x2 on the memory. http://download.intel.com/support/motherboards/desktop/d915gag/sb/c6860002.pdf this is your Motherboard?
pgs 85 to 86 give the temps? Jazz

 

jazz.. this is the board in the other system which works fine. the one that has issue is a D945GCNL board.