Very Old mobo + Old CPU dilema

[Ultra_Bloodshed]

My friends are throwing away their old stuff so I thought I'd gather those parts and assemble a system for casual stuff. This are the mobo and CPU I gathered.

MOBO: ASUS M2N-MX SE
CPU: AMD Phenom II X3 720

The Asus board is based on the AM2 socket. The CPU is AM2+ or AM3 socket based, I am a bit confused. As far as I know, AM2+ and AM2 are backward compatible.

But after assembly, the system fails to boot up. On power on, the CPU fan rotates for 2 secs and shuts down. I am guessing it's "rejecting" the CPU.

What am I doing wrong? Are they incompatible? Do I need to update the bios in the mobo? If so, how do I update something that won't boot!

 

[coderunknown]

it won't support any AM3 processor.

 

[Ultra_Bloodshed]

Ummm... why not? All AM3 CPU are backwards compatible with AM2/AM2+ sockets.

 

[coderunknown]

nope. AM3 cpu are backward compitable with AM2+ socket, not AM2 socket. and that board have AM2 socket & so will support maximum of AM2+ only.

 

[topgear]

@ OP - here's the cpu support list page of the mobo
ASUSTeK Computer Inc. - Motherboards- ASUS M2N-MX SE