I have seen similar topics about this bug/problem but I don't know if it's motherboard's or processor's fault.
So, my specs : AMD FX-8120, MSI 990FXA-GD65, 8Gb DDR3
When I bought the motherboard, I put the latest BIOS version (19.8) and I experienced these temps only when I had unplugged the PSU cable before starting up the computer.
With the most recent BIOS (19.9), everytime I turn on the computer (2 hours from the last switch off) I see these temps :
Notice that 255° C is min/max CORE temp, CPU/MB temps are normal.
If I stess the system (100% CPU activity) it won' t go over 1400MHz :
And of course the stress program fails with these CORE temps :
After I simply restart the computer, all go back to normal, it idles and stresses without problems and temps are fine.
So, 255° C CORE temp everytime system boots (with BIOS 19.9), CPU can't go over minimum frequency but CPU/MB temps are fine. And after a restart all go back to normal.
Is it CPU or Motherboard?
If it's processor's fail can I ask for replacement?
Thank you for your time,
PS : I have posted the exact same thread here --> http://forum-en.msi.com/index.php?topic=162839.0 (maybe their answers help you)