hey I've got a p4 1.7 ghz w/ 350 watt power supply 1 gb sdram pc 133 300 gb hd, 20 gb hd, ATi x700 Pro 256 mb gddr3 and dvdr drive.

My compuer randomly shuts down esp when running any heavy applications, or even windows media player, it stays off for like 5 min. I can't turn it back on for more than like 3 - 5 seconds after it shuts down and have to wait the 5 min. I thought it was my power supply so i bought a 500 watt power supply and now its doing the same thing over again,
any ideas?

Where do you keep your PC? It's probably overheating (P4's tend to run hot).

get a better heat sync and fan...

A good starting place was the power supply, all the components in a PC can take up a lot of power, including those which you add in after you get the machine; however the fact that it stays off points directly at a cooling issue.

As said twice before; you'll want to invest in a better heat sync for your processor and perhaps a few case fan's or other cooling devices.

So a new heat sink and better cpu fan, and clean out the old case fans.

Now however, the system temp runs at 28 celcius while cpu is at 50 celcius. There is the obvoius fan from the power supply, the cpu fan, and two case fans, so Im just going to try the cpu fan and heatsink idea, but if this doesnt fix it, I hope to god my cpu isn't dying, becuase thats even more $ to toss out.

I figured it was either one of the three and I went in order, Powersupply, RAM, Fans/Cpu (overheating). Got the new powersupply, RAM - removed a 256 chip, so it was just two 512s in the board, instead of 2 512s and a 256 (someone told me that it was probably the problem beinga different size chip - but i thought it didnt matter as long as it was same mhz and type [ie. pc133 vs 100].

See, whats happening here is a new feature (within the last 7 years or so) that actually turns your computer off in order to salvage your processor; hence why you're not able to turn it on ... Your computer takes and gets a redout of how well the CPU_Fan1 port is functioning and judges "well, if it's this sucky here I'm just going to turn myself off"... Always be sure to plug your cpu fan into the CPU_Fan1 port; there should be a BIOS swith to disable this functionality, though it's not reccommended at all to EVER touch this switch as it's there to save your hardware

What CPU/Fan are you using out of curisority?

BTW, it's not your ram, go ahead and put the stick back in.

If you want to know if your CPU overheats do the following :

1. Reboot your computer and enter BIOS.
2. Go to PC Health Status.
3. Make sure that the "CPU Warning Function" is enabled.
4. Set the "CPU Warning Temperature" and make sure it's lower than the "CPU Shutdown Temperature".
5. Save and Exit.

In my BIOS the CPU W.T. is set at 70ºC and the CPU S.T. at 75ºC. (I have a P4 1.8 GHz CPU)

The next time the CPU reaches the CPU W.T. you'll hear an alarm. If your computer shuts down out of nowhere and you don't hear an alarm before that happens, it's not the CPU.

You should at least try this before buying a new heat sink, CPU vent, case vents, etc.

Thanks, I'll try these tonite after work. I'll let ya all no what happens.

yea have passed out last couple of nites, anyways, its plugged into the only cpu fan and the bios has only a chutdown max temp and its disables because the temp never reaches that height.

my shot in the dark says its the video card. If the video card is going out it can cause a hardware conflict and whammo it shuts down.

Isn't the video card, just bought it within the last 2 months. I decided that I would try cleaning out the case fans, cpu fan and heatsink, and disconnect and reconnect everything, so happens it works now. I've been trying to crash it again using extensive programs and games, and it seems to be running fine, ended up being the fans i guess. BTW after cleaning the fans and the heatsink, the temp went from 49 degress CPU celcius, to 41 and hasn't raised. Sys temp is at 36 degress celcius

Sorry if this is a bit off topic or something but i didn't have the time to read the whole thread. If you looking for a heatsynk for a 1.7 ghz get a 3D Rocket Cooler they are cheap and hell of an effective. I use it on a 3.0 ghz

I like Thermaltake heatsync's myself; they're rated everywhere as some of the best heatsync's available and they make them for every type of processor.

Additionally for Thermal Paste I like Artic Silver