Strange PC Shut-Off Problem

[atn2002]

About once a month my computer will start acting up. It will begin
shutting off randomly for a few days and then be perfectly fine and
solid for a few weeks until it starts it's "time of the month" again.
I'm thinking the PSU but it's just strange to me that it's not
constant. I've reformatted and it still happens (once it couldn't even
make it past the BIOS until after about 5 reboots...then it ran fine)
Any one have any idea's?

Windows XP Home SP2
Athlon XP 3200+ (2.2ghz)
DFI NF2 Infinity w/Soundstorm
1GB DDR400 (2x512mb)
Radeon 9800 Pro 128mb
WD Raptor 74GB 10,000rpm (SATA)
WD Cavalier 160gb 7,200rpm (IDE)
Deskstar 60gb 7,200rpm (IDE)
Maxtor 40gb 7,200rpm (IDE)
LG 16x DVD+/-WR (USB2.0)
Enermax 350watt PSU
Epson Stylus CX5400
Logitech DiNovo Laser (Keyboard/Mouse)
[Kerio Personal Firewall - AVG Free]

 

[atn2002]

I should also mention, it's on a 1200va UPS, which doesn't make a
difference towards this behavior.

 

[johns]

Run a ram check .. from a cd boot if possible. You
could be just hitting a bad spot in ram that is far enough
downstream as to be rare. Bad ram will many times
just reboot the system.

johns

 

[atn2002]

I thought of that, rare spikes in power draw, but weeks on end between
sudden barrages of spikes would seem like there's something more behind
it. I did the ram check too; turned up flawless. I'm thinking
(hoping) it's the video card heatsink as I mentioned and hope that my
rigging will hold up just a few more months! ;-) If not, well, I'll be
able to live with it for now as long as it doesn't get worse. The
"time of the month" behaviour leaves me baffled though...

 

[atn2002]

I thought of that, rare spikes in power draw, but weeks on end between
sudden barrages of spikes would seem like there's something more behind
it. I've completely gutted it and cleaned out all the dust bunnies
recently. I also did the ram check; turned up flawless. I'm thinking
(hoping) it's the video card heatsink as I mentioned (perhaps bumed up
with dust that I can't see and get at; lots of tight fins) and hope
that my rigging will hold up just a few more months! ;-) If not, well,
I'll be able to live with it for now as long as it doesn't get worse.
The "time of the month" behaviour still leaves me baffled though...

 

[atn2002]

Obviously the four hard drives are using a lot of power so one might
wonder why I have so many hard drives. I highly recommend it:

WD Raptor C: (Windows/Programs)
160GB (Media)
60GB (Work/Business)
40GB (Downloads, etc)

Not quite Raid but something about having the heads searching for
program files, while accessing spreadsheets separately while background
downloads are slowly streaming to a different hard drive and mp3's
slowly streaming off of yet another hard drive feels really solid!!!
(Also having Work files backed-up nightly to the large media drive.
And of course downloads seem to cause a lot of fragmentation so keeping
them seperate is good)
Different types of tasks running simultaneously from different hard
drives is the way to go; I don't think I'm imaging it.