PC just turns off randomly

[JGY6000]

my pc has started to just restart when it feels like it, i could be doing somthing ( like in WORD or just surfing the net) and it would give no warning or anything and just go clunk and restart

any ideas?

[lllN30lll]

Harddrive on the way out?

overheating?
____________________
Turbo R1
CRF450R

[JGY6000]

i have recently added another gig of ram (was on 512) but apart from that i havent done much, i did not long ago replace all the IDE cables with round braided ones to improve air flow and general mess in the case,

how would i find out if my HDD is on its last legs?

[pwntifex]

It will be your RAM.
Mine used to do this, usually when I ran something that was memory intensive, like HL2. Take the stick of RAM out, and see if it continues to reboot itself. Most probably won't.

A lot of mismatched RAM won't run properly; it's always best to get identical sticks.
____________________
the warped one: This is a follow up from the thread 'my willy hurts'

[JGY6000]

they are all identical, i bought the 2 extra 512mb (1Gig) using the info written on the original

[ProXimaCore]

Overheating is what I would say. PC will reboot itself if the CPU gets too hot. One of my old pcs used to do it. Could try re-seating the CPU with some fresh heat compound.
____________________
Honda NSR125R -> Suzuki GSXR400R GK76a -> Kawasaki ZX636 B1H -> Honda CBR400RR NC29 -> Nothing

[Rhys]

get a hoover to the fan, sorted overheating on my laptop out.
____________________
Current Bike: '94 RVF 400R
Bike Pics Youtube Myspace

[techierob]

1. overheating PSU/CPU
All off-the-peg AT-X PSU's will cut out if they get too hot and the BIOS will signal the OS to shut down if it detects that the CPU is too hot.
Some AMD systems have a fault that causes the BIOS to misreport the CPU remperature causing the system to shut down unnecessarily.
PSU and CPU temperatures should be shown in the BIOS, so you can get a pretty good idea of the running temperatures by checking them immediately after a shutdown.

2. RAM fault
Are you certain that the RAM sticks are identical? If they're different manufacturers or the chips on one stick differ from the other, then they're almost certainly not the same.
Mixing ECC/non-ECC, parity/non-parity RAM can lead to software faults that would be almost impossible to diagnose. The speeds and ratings might be identical, but the RAM could still be incompatible.
There's also a possibility that the RAM (even if it's new) has faults on it. Check that the RAM test at boot is testing all of the installed memory and try running memtest86 off a knoppix live CD to do a thorough test.
Similarly, bad blocks on a hard disk could lead to corrupt memory when virtual memory is paging stuff to disk. The badblocks utility on a knoppix live CD should spot this.

3. Motherboard RAM-chip fault
These faults seem to be increasingly common for some reason. memtest86 spots these problems about 50% of the time, but there's nothing you can do about it short of changing the motherboard.
If this is the problem, then other symptoms might include CRC errors appearing when testing large archives and inexplicable disk verification errors when burning cd's/dvd's.

4. Software fault
If you're running windows, then it could be the result of a virus or trojan going spazzy. Simply test the system under load with a live cd and see if the problem still occurs.

5. Overheating GPU
Are you sure that the entire system is shutting down and that it's not just the screen going blank? Modern graphics cards run very hot and can frequently cut out.

[GodzGift]

as rob suggested most of causes of the issue, i would go all in on overheating