complete shutdown

[the crazy 1]

Hi all

i have a weird problem with my pc I get a NEE NAW sound for a few seconds then the computer turn itself of completely and when i turn it back on it is fine. It does it at different times sometimes it will be on for hours and other times are shorter there is no other warning i will be working away then i get this noise and thats it the computer is off. I have checked the system fan and that is working, and the cpu fan is working i have pushed in the graphics card but it still happens any ideas i would be gratefull

[PrntRhd]

The sound may be the floppy drive cycling before shutdown, most have a LED that lights when they groan. The question is why it is shutting down in the first place.
What OS?
Do you have Advanced Power Managment turned on, what settings there?

[the crazy 1]

I don't have a floppy drive installed. i have checked all leads. I have changed the video card, the cpu temp is about 84 degrees think thats ok i have checked my power settings and think they are all ok. when i leave the computer i have been putting it in standby mode and it seems ok it is only when it is in normal mode there are problems, but it is so unpredictable it may run for 5 hours or just a couple but it don't give me anytime to save things
i am running win xp.

[ErnieK]

Next time it happens pop intothe BIOS and check the temprature. This could be the emergency shutdown/alarm due to heat that some BIOS's have built in

[Paleo Pete]

the cpu temp is about 84 degrees think thats ok

Is that Farenheit or Celcius? 84 C is NOT ok...

I think it sounds like heat too, especially being erratic. The "siren on drugs" sound, as I call it, usually means something is seriously wrong, like no RAM or CPU detected. If the CPU gets too hot that could easily be the warning tone to let you know it. On older DOS machines like 286 boxes, I think it was a no boot device or no ROM BASIC error sound.

Check your motherboard manual, if you have one, and check BIOS to see if the thermal alarm is enabled. Also check to be sure the CPU clock and frequency settings are correct. If the machine is overclocked, by all means set it back to normal for troubleshooting, overclocking side effects is the first thing to suspect if that is the case.

Also make sure the CPU heatsink is not coated with dust and lint. A can of compressed air or a small brush can help. Make sure it's not a stiff brush... I use camera and make up brushes.

[the crazy 1]

Thanks
checked all the settings the system temp is 31 c and the cpu temp is 84 c
all the other settings seem to be ok. what should the cpu temp be and how can i rectify the problem could it be the fan or the cpu
thanks for all your help.

[david eaton]

84Cis very near frying temp! Check that the heatsink is fitted correctly, with just a smear of thermal compound, or a new thermal pad.
New heatsinks come with a thermal pad already fitted, and a clear plastic protective layer over it. You did remove that protector didn't you?