Since your Motherboard has a AM2+ Socket, here are all the compatible CPUs that would fit and work in your motherboard: http://www.cpu-world.com/Sockets/Socket%20AM2.html
See if any of these are listed on your Motherboard CPU list:
This is an excellent CPU Website that gives you all the Specs on all CPUs made. http://www.cpu-world.com/CPUs/K10/TYPE-Phenom%20X4.html?gt_f1=2>_f2=%2FCPUs%2FK10%2FTYPE-Phenom+X4.html&process=Go&got… This page is for all Phenom II CPUs. Pick one and read the specs to compare with other similar CPUs for your motherboard.
But your Motherboard also supports AM3 CPUs. AM3 is backward compatible to AM2+ Sockets. AM3+ CPUs are not compatible. Socket-AM2, AM2+ and AM3: Backwards Compatibility - AMD Phenom II X4 940 & 920: A True Return to Competition
Look at the CPU list for your Motherboard and see which CPU you want to update with. Just make sure you have the appropriate BIOS installed for your CPU from the list. It mentions which BIOS you need for which CPU. If you can afford it, I would try to install a AM3 CPU which are faster and better than AM2+ CPUs. CPU List from your motherboard: ECS > A780GM-M3 (V1.0)
This is the QVL (Qualified Vendor's List) list for the type of RAM Memory that has been tested to be 100% compatible with your motherboard: http://download.ecs.com.tw/dlfileecs/manual/qvl/1_QVL%20of%20A780GM-M3%20(1.0).pdf?Policy=eyJTdGF0ZW1lbnQiOiBbeyJSZXNvdX… Downloaded from your motherboard's Support Site.