Does sempron 140 work in this board

Can't say for sure. It may work, as the sempron 140 is designed to work on am2+am3 or am3 only boards; if you can't sell or return the cpu, I would select an older sempron core. I found a used 2400be dual core with similar performance for $38 shipped on a hardware for sale forum.

ty for the reply. i am mainly concerned if the cpu or something will get burned if the board doesnt support it?

The cpu won't get damaged; the board simply won't post with it, or it might post as "unknown cpu".

ty very much , i have to try it .

There is a 99.99999% chance that it works. I almost can guarantee it 100%. It is not on the support list but even the high end AM3 Phenoms are there so why an AM3 Sempron wouldn't work wouldn't make sense.

Is this motherboard one you already have? If you don't have this already you can get a great AM3/ DDR3 motherboard for like $65. It is ASUS too.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

To answer you question about memory. It uses DDR2 which is clearly stated....so that means you cannot use DDR3 although the Sempron has support for DDR3. DDR2 only.

But seriously, if you can get a different motherboard, you'd be much better off.