June 28th, 2004, 02:29 PM
Fan on laptop does not spin
I bought a new motherboard for a presario laptop and tried putting in the old parts from the old laptop. Everything works except the fan. I have tried two different fans with the same voltage and both fans do not work. Without the fan this laptop is no good. What are the chances that everything on the motherboard works except the fan connector? Slim to none I think. I think that the motherboard is fine, and there is some trick to get the fan to start moving. I just don't see it. Someone told me that the fan is automatic and that it will only spin if the CPU is hot, but I thought that initially when you power up your laptop the fan has to spin anyway. What am I not seeing? Also, I have only tested the fan with the laptop disassembled. May be it is not spinning because the CPU is receiving a ton of air with the motherboard open, and it does not have a chance to get hot. I would like to test the fan with the laptop disassembled because it does not make sense to put the laptop completely together and then take it apart again. That is tedious and will take forever. Also, I know that none of the othe parts contribute to powering the fan except the motherboard itself and the heat from the CPU. How can I get my fan to spin and test to see if the fan connector on the motherboard is really working? If all else fails perhaps you guys can direct me to a website that teaches you how to hotwire your fan directly into the motherboard. I have never done this before and may be now is a good time to learn. My laptop is in the Compaq Presario 1600 series.
Thanks for your help.
July 13th, 2004, 08:04 PM
i think you can hotwire the fan to the system circuit, so whenever you switch on the comp, the fan starts to roll.
with a multimeter find a 12VDC+ point, a good place is the hdd connector, or the processor support core backup voltage pin, you can use a source just after the main switch (thats the safest) when the power is just flowing into the system.
and then connect the positive (red) wire there and the negative (black) one to the battery negative terminal.