Answer to: iMac Intel 2133 Logic Board ReplacementHi Sook, From the photo it looks like you have exactly the same logic boards, but there are some additional components on your old board that are probably sold separately, thus it looks like the boards are not the same. IMO it is not a complicated task to move the extra parts to the new board, I can't see any soldering required, just removing a few screws and re-attaching the parts to the exact same location on the new board. Worths giving it a try. If you don't feel comfortable doing it by yourself, take both parts to a computer technician, they will probably do it for you in minutes. Good luck
Answer to: Replacing failing hard driveA failing drive may trigger the HDD fan because it may warm up, and the result would be pushing your HDD fan to its max rotation (around 6000 rpm) and this may not be a pleasant experience, therefore it is advised to remove or replace that drive.