I just assembled a new computer using a DH55HC Mobo and a i5-650 CPU. I installed the Intel CPU fan which came boxed with the i5. THERE ARE NO INSTRUCTIONS at all with the MoBo so I am a tad nervous about starting up. When I powereed up, all 6 of the case fans and the Video Card fan came on. The CPU fan did not. I shut down immediately. The CPU fan is the only one with 4 wires. I thought that it was possible that the fan will not come on until the processir gets hot enough to tell it to. I AM NOT GUTSY ENOUGH TO TRY WAITING. With no power on, the fan blade is free to spin but there is a great deal of opposition which feeels like the magnetic fields at 60 degree intervals. When I turned the power on momentarily, the fan did lurch buit did not spin.
QUESTION Is the fourth lead to that fan a sensor which controls the fan? Should I try booting and see if the fan comes on eventually? If so how long could I leave it on before damage due to overheat would become an issue.
BTW I got to this point at 8:05 Eastern time Friday night Phone support will reopen in 60 hours
I can remove the fan and rotate it 180 degrees to where it might reach the "rear fan" connector which is lso a four pin connector. it is open because all of my fans except the CPU fan have 3 pin connectors. I do not know and will not know if there is power to that connector unless the fan does run from there. What is the fourth lead for?
In the process of moving the wires, I discovered that one of the wires was stretched taught enough to be restricting the fans motion. MY SYSTEM IS UP AND RUNNING. I am finding that the CPU is running at 75 degrees F, while the system runs at 83 Degrees F. I will research further Does the BIOS control the fan speed as detected by the fourth lead