I have a 21.5 inch iMac EMC 2544 (late 2012) that had a bad logic board. Well i replaced the logic board, replaced the old memory from the previous board and now when i try to boot the computer it gives me the one beep after every 5 seconds EFI tone suggesting that there is No RAM installed on the computer. Well there is in fact two sticks of Ram installed. I tried removing the new board again and switching the order of the sticks (both of same brand and memory size, again ill reiterate that the RAM now inside the machine is that of the old logic board that came with the computer.) I cant figure out why it would do this and since there is no boot at all it does not boot into hardware test mode.