The Most Bizarre System Lockup Issue You Will Ever See

"Although the timeframe isn't as long I've seen this sort of lockup with the hard drive light on from the ICHR9 drive controller that's on so many motherboards. I've never had it happen on a new board, only after a few months. As it gets worse it will lead to periodic BSODs.

This box used to suffer the lockup bit and then started BSODing. I finally slapped an add-in drive controller in and ran the main drives off it (the optical is still off the MB) and I haven't seen a lockup nor a BSOD since I did that. No other hardware changes, the only software change was the addition of the driver for the new card.

The miserable quality of the support software that comes along with the ICHR9 makes me suspect they were as sloppy with the hardware. The program for configuring the system once the OS is booted can take 20+ seconds to refresh the drive status--and it will do so as part of the screen repaint, including as a result of any click. At least you don't have to run that, but the driver that runs it is another matter--the version that shipped with the board leaked about 100,000 handles/hour. This would eventually kill Windows or eat up so much memory that you had to reboot. A later version of the driver at least fixed this problem."

"This almost sounds like an IRQ flood causing the CPU to spend all it's time doing essentially nothing. The first thing I would try is this. Pull every non essential card and wire. You've already replaced everything essential. You can also boot from a Live CD as another suggested. I would turn off all the hard drives in BIOS if you do. This would eliminate the drive subsystem.

I would even move the PC to another power source and use a different monitor/video card. This is essentially a shotgun approach, but if you can prove that the problem can be eliminated, then you know you've isolated it. Then you can start working back the other direction and add components back until you re-introduce the problem. Once you narrow it to the correct subsystem, you will know where to look.

Always remember in any problem, there is the trigger and the failure. It's the trigger you have to find and eliminate. It could be external. If it's physically connected, it's a possible factor. You may have to literally ""think outside the box"". Good luck"