Achim: if you measure IHS temp, you'll have to modify the IHS and install HSF on top sitting with a good flush contact and the probe underneath at the geometric center of the chip within the IHS. So the temps will be higher than taking any side measurements. X2 works differently to K10h since the core DTS can give different temperature feedbacks and the BIOS interprets them differently.

SmartGuardian is +20C wrong pretty easily looking at the various values. The next time you get the Phenom, open HWMonitor as well to checkup the various readings. Plus your CPU temp in EVEREST only showed ~53C actual around -10C with M3A readings and what every other Phenom gets. Every Phenom I've seen so far gets far lower temps than those at similar volts/speeds.
Measure the RD790 temp when you get Phenom, that was giving it a 52C reading. From personal experience I know RD790 is a 10W TDP chip and never reaches even 40C at <30C ambient, so those are near 32C actual temps it was reading as 52C, a +20C offset.

I don't think the temps/speeds killed the CPU IMHO, but I'm not sure if feeding the CPU/RAM high volts and priming it did. What's the max CPU VID and voltage you've ever fed it?

Kinda strange why it doesn't boot.

BTW, your sig reads you have a Phenom 9500 running a Phenom 9600 multi.