Computer shutting down by itself
 

as title says, my pc randomly shuts down. i believe it's overheat(?) since it mostly happens when my pc is under heavy load and it starts making some weird "alarm" noises, anyway to check it?
first time having problems with this kind of stuff... i recently upgraded my pc, so i was thinking maybe power supply is not enough?
-PSU 600W (Thermaltake) [recently changed]
-AMD HD 6870 [recently changed
-Biostar TA 790GX (old)
-4GB Ram ddr3 (old)
-AMD Athlon II x4 620 (old)

No your power supply is more then enough for your PC. Run some stress tests to isolate what is causing it with a app to monitor temperatures. I think it's because your CPU is overheating but that's just my guess.

how does the alarm noise sound like.
There's possibility that it might be overheat check if your heatsinks are properly seated.

thanks ill do that a bit later, got some stuff to do atm, will post results later
mmm the alarm is like a beep beep, not sure how to explain i could try to record it... but not sure where to upload it

the beeps are usually specific, it'll tell you what the problem might be.

Usually (mobos I've had), when your system shuts down from overheating on the CPU, you should get a message during POST that requires confirmation that you know the system overheated.

a little update on this.
i've run everest to check on temperatures and after shutdown, i turn it on immediately but no message appeared, what i did saw was CPU temperatures going around 77-70 ºC, not sure if that is normal or something.
i think i've already mentioned i believe it only shuts down when im doing heavy load task or heavy multi tasking.
on the beeping sound, i looked it up and i cant seem to find a stable "analysis" they appear randomly and sometimes they are totally different

edit.

used also speedfan to test temps. now im 99% sure its CPU overheating, tested under some load, reached 80 to 90ºC

http://img542.imageshack.us/img542/2208/12758246.jpg

speedfan isn't 100% accurate but it gives a good indication of where the temperatures are at. that's pretty hot and most likely you probably have your BIOS CPU temperature alarm set to that to a temperature near under load which is why it's giving you the beeping noise. your cpu is running hot and you could probably use a new CPU cooler, case plus thermal grease.

edit: the newest version of speedfan is a lot easier to read btw.

any recommendations on cooling? i dont really wanna spend a lot of money on a cooler... need a new psp :3

which brand of cpu and chipset do you have? oh and your current case info too if you can.

AMD 790GX Chipset and AMD athlon II x620, the case is Overcase Ov 517... it's a normal case but i think it might also influence on the overheat problem since it sucks major ****, unfortunately it was the only thing available for months at the time of purchase.

what i had in mind
-Cooler Master Hyper 212 Plus
-Cooler Master Hyper Tx3 - 3 Heatpipes

I'm using the hyper 212 Tx3 and it keeps my CPU nice and cool but I also have a lot of air flow in my case. I would have recommend the Xigmatek Gaia to save a little money it's a 120mm fan version of the Tx3 but I don't know if I had the correct dimensions of your case (24.5cm/9inch width?). If you don't have aftermarket thermal grease, I would recommend buying some since it does help lower temperatures.

i measured it and it's 45 ish cm tall and 18/17 ish cm width

edit.
465x238x526 are the measures according to the official data but i have no idea in what they're measured :/ im gonna guess mm?

looked at a few cases, thermaltake v3 black edition was quite cheap and looked good, opinions?

I would aim for a case with better airflow.

Newegg.com - Sentey Optimus Extreme Division Tower Case - RED 3 x LED FAN / 1 120mm Rear FAN /2 x USB / Card Rdr / Fan Control /4 x Removable Bays / Screwless

if you have thermal paste you might want to just reseat the heatsink. (clean off the old one first)

Poor heatsink contact can cause it.
Also it might be the chipset overheating as well. (not sure which is the system temp)

you might also want to try adding a fan behind.

alright, thanks guys for the tips, ill update the thread once again when my stuff arrives. also i just noticed, that speedfan reads one fan at 41 rpm ._."