X58a-UD3R rev2.0 semi-bricked

[MartinC]

Hello,

I've been using a GA-X58A-UD3R (rev2.0, bios FH) in my main PC* for 4 years now.
I used it under Win 7 and OS X Mavericks.

I'm experiencing a weird issue since yesterday:

The system will POST but will absolutely NOT boot any OS, not matter what medium it is installed to (USB, HDD, DVD, SSD).
I can get to the bios or F12 boot menu, but right after drive selection (if a bootable drive is chosen) the system reboots.
So far I tried with Windows 7 Install DVD, Linux CD (PartedMagic), Linux USB drive, ...
The only thing that goes beyond boot menu is a DOS-formatted usb disk with FLASHSPI.
Since my bios revision is FH, FlashSPI refuses to flash a <1MB BIOS file, so I've only been able to revert back to rev FG1. Reverting back to an older BIOS revision via backup BIOS is impossible, since I updated it to FH (via alt-F12) few days ago.

I performed usual things like various CMOS resets, let the system rest uplugged with battery removed for the night, ... Tried with a known good 4GB Ram stick,... no luck so far.

Any idea, guys ?

Thanks,
Martin.


EDIT : tested with another graphic card and a known good PSU, nothing change.
If booted from a Memtest86+ USB stick, system reboots after 3-4 sec

* GA-X58A-UD3R rev 2.0, Intel Xeon X5660, 3x4GB Corsair Vengeance 1600MHz kit, Crossfire AMD HD7950 GPUs , 512MB Crucial SSD, 2x2TB Samsung HDDs, 4TB WD Red HDD

[MartinC]

Well, I grabbed another CPU (I7-950), installed it and guess what : the system now boots 
Never seen a CPU failing before, but I can't see any other explanation.

Case solved.

[LostOblivion]

I suddenly have an issue with this too on my UD3R, with an old 1st gen i7, but only when the OS is on a disk connected to the Marvell SATA3 controller.

Could it be something with the latest BIOS version FH?