I had a problem like this with a msi motherboard recently, the processor i bought for it (e8500) was supported in the new firmware, but not whit the firmware that came in the box.
Had to buy as cheap a processor i could find that worked (celeron e1200) and boot with that, flash the firmware and then i could use the new processor.
It did the fan spinup, stop, reboot loop too.
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Empeg Mk1 #00177, 2.00 final, hijack 4.76