Problem: Random Restarts, won't shut down entirely

[timheerebout]

Hey All,

I built this tower a couple of months ago. Generally I'm really happy with it. However, it has a tendency to crash when it's not being used (has never crashed when in use) and when it crashes it tries to reboot unsuccessfully for as long as it takes me to notice it's crashed. Weird? I don't even know where to begin.
It also does not shut down properly (only way to turn it off is to hold in the power button).
Any guesses as to where my problem lies? I bought all of the hardware new from newegg

 

[cmichael138]

And what are those parts?

 

[masterjaw]

List the specs first.

 

[timheerebout]

HD - Western Digital Caviar Black WD6401AALS 640GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM
CPU Cooling - XIGMATEK EP-CD901 92mm Sleeve CPU Cooler - Retail
Case - Antec Three Hundred Black Steel ATX Mid Tower Computer Case - RetailGIGABYTE GV-R467D3-512I Radeon HD 4670 512MB GFX - 128-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
MB - GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard - Retail
PS - Antec EA650 650W Continuous Power ATX12V Ver.2.2 / EPS12V version 2.91 SLI Certified CrossFire Ready 80 PLUS Certified Active ... - Retail
RAM - G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Desktop Memory Model F2-8500CL5D-4GBPQ - Retail
CPU - Intel Pentium E5200 Wolfdale 2.5GHz LGA 775 65W Dual-Core Processor Model BX80571E5200 - Retail
OS - Windows Vista

No over clocking of any kind.

 

[masterjaw]

Hmm.. must be software. Did you try to reinstall your OS and drivers?

What do you mean by "it doesn't shut down properly"? What happens when you do the normal shut down?

 

[timheerebout]

ok so back to this...I tried updating drivers this week and it did nothing
In addition, I need to correct myself...the OS DOES shut down properly...however the power will not turn off fully until I flick the switch on the power supply...if I don't do that the machine will, of it's own accord, try to restart itself ad-infinium until the power supply is shut off. This attempted restarting causes Windows to sense that it doesn't shut down properly.
Also, it seems the crashes are happening only when the computer goes into idle mode...which leads me to ask if there is some kind of power setting in either the BIOS or OS I might need to change....perhaps a power saving mode or something?

 

[timheerebout]

bump

 

[masterjaw]

How did you know that the power isn't fully turned off? Fans and hdd still spinning or the lights inside the case still lit up?

 

[timheerebout]

ok so upon further exploration it seems everything does fully turn off...however after about a 2 second delay the whole thing will attempt to turn itself back on again. If the PC was properly shut down then the attempted restart seems to be successful. However, if the PC crashes it seems to simply attempt and fail at restarting itself ad infinitum until I shut off the PS, wait 5 seconds and then power it up again.

Should I make a video of this? Would that be helpful?