P55A-UD3R Unstable Random Shutdown, then Restart

[beatmag]

Hi all,

recently got a P55A-UD3R with i7-860.
4gb Kingston Value DDR3.
550w coolermaster psu, a little old.

Line-Load CPU off.
ram 1.54(normal) or 1.58 (auto)
everything else on auto
NO OC.

I have a usb audio device plugged in all the time.

The issue is , it sometimes just seems to shutdown, then 1-2seconds later restarts itself. it seems like it lost power then, it started itself back up.

I consistently get this after 30min of idle. Now its happening more often, even on a win7 installation.

PSU does buzz alot when the EIST and C1E and C234567 are on.

I have no idea what is going on.
It seemed to be unstable, since I installed the Noctua U9B-SE. I followed the instructions and it says tighten the screws till you cant anymore.

helpppppppppppppp

[Pottypete]

Hi
Have you checked ok with usb disconnected,
Is your Psu ok, try another if you can,
Is your cpu temp Ok,
Remove the Noctua cooler and fit std cooler assembly and see if ok, if it is check your fitment of the noctua,
Have you fitted the cooler with cpu  heat paste,
Cheers
Def seems like a cpu temp shutdown to me,
Cheers

[beatmag]

Temps are fine. 57 degrees max load.
Stock cooler was 83 degrees.

Yeah noctua was fitted accordding to instructions. Thermal paste also applied moderately.

I've tried so many things its all failed.

I will try removing USB to see what happens.
Then try a new power supply that I will buy soon. 

What is the acutal shutdown suppose to be???
Because in win7 there is no log. It just appears to have lost power unexpectedly.
My power supple is old and is buzzing a little when the c1e and eist kick in.
But my new oxides the exact same power as my old one.
Also the +12v rail seems to be wrong in speedfan. When there is no load it says something weird like 1.5-12. When it's on load it's in the 11 to 12 range. All the other voltages seem ok.
 

[beatmag]

Does Kingston value 1333 run with 2T or 1T Bios has autoed to 1T however I'm not getting crashes and it passed memtest86 also prime 2hrs. The only thing is random shutdown then restart randomly. Seems to do it when idle. Had it sonetimes in win7 install.

Also there are no beeps nothing when it shutsdown. It just goes zap. Then 2 secs later beep bios post. 

[beatmag]

I have now removed the USB audio device.
Changed the Memory command rate to 2T.
Last night left it on, it never rebooted.

This is all with the same setup.
I have yet to buy a new PSU.

does anyone else have any more ideas?