Why is my CPU fan running full speed?
I bought a used iMac and the CPU fan is on full speed, all the time. As soon as the computer boot chime is heard it starts up and stays running full speed. Using guides here I took the computer apart and discovered it is missing the LCD temp sensor and cable. Would this cause the full speed CPU fan, or is there a good chance there may be additional problems with the logic board even if I replace the missing sensor?