CPU overheating on one motherboard, but not another

[fez]

I just got a new motherboard, but when I put my existing processor in it, the processor overheats immediately (up to 85 just starting up).

Swapping back to old motherboard, all is fine. Back to new one, overheats again. Both using the same Skythe Ninja heatsink.

New motherboard: Gigabyte GA-MA78GM-S2H 780G Socket AM2+
Old motherboard: ASUS M2A-VM HDMI
Processor: AMD Athlon 64 X2 4200+ Socket AM2 (2.2GHz) Energy Efficient

The new motherboard picks up the processor ok in the startup screen. I've updated to the latest BIOS, and the gigabyte site says the processor is supported by the board.

Any ideas?

Cheers

[augiedoggie]

Erm, this may be an insulting question but did you clean the surfaces and change the the thermal compound? For the one that overheats, is the fan working? 85C is just insane man, lucky you didn't fry it assuming the heat sensor works properly..

[fez]

Thanks, but I did clean it all up, so I don't think it's that..

Cheers

[dlb]

I'd check the old mobo BIOS and make a note of what all the voltages are and compare them to the values listed in the new mobo BIOS, do the same for the fan speed readings. Some BIOSes on newer boards have settings for different fan speed levels; Slow, Normal, Med, High. Maybe the default is slow or even normal and perhaps it's too slow for the CPU. Also check the heat sink retaining bracket on the new board (the square of plastic around the CPU socket that holds the heatsink in place) and make sure it is fastened to the mobo correctly. I've seen 'em where the mounting screws were loose which resulted in poor contact between the CPU and heat sink....