If you see “21 B6 E1 E2” on your screen or diagnostic LED, your board is likely a Intel 6-Series or 7-Series chipset board (e.g., H61, P67, Z68, Q77, B75). The most common suspect is the Intel Desktop Board DH61CR or DP67DE .
or similar 2nd and 3rd Generation Intel Core (LGA 1155) motherboards. intel desktop board 21 b6 e1 e2 specification link