hello sifus , im planning to use 2 pieces of 12CM fans to become a laptop cooler.

however , i do not know to convert the 3pin fan pins to USB =/

any idea sifoos?

try to find a dead mouse, then cut out the USB cable from there...
later use multimeter to find pin 1 & pin 4 cables and connect to case fan's power pins
as theoretical should work... so try it at ur own risk...

anyway, USB Pin 1 & Pin 4 only deliver 5V voltage, so a bit struggling for case fan to cool your laptop efficiently... in order to avoid any unnecessary damages, recommended to find a power adapter which deliver 8-14v DC output and plug ur case fan onto it...

This post has been edited by gkl83: Feb 22 2011, 01:33 PM

Just go to buy a 12V power adapter to just connect ur fan to the power adapter

and then u need to think of a way to arrange/hide the ugly sight of the wires..
but be very careful in joining the wires together..make sure it's the right polarity..

TS just needs to find low amperage fans so as not to overstress the USB port...

ive done this mod before.. connected two 12cm fans to a single usb cable/port.

i had this mod connected to the USB port of my office's NAS....and it has been running 24/7 for the past 3-4 years with no issues watsoever....only stopped to clean off dusts every now and then...last cleaning oso was about 2 years ago.....still running til today.

but ull definitely need a multimeter to figure out which wire is which. coz inside the USB cable is 4 seperate cables of different colors.. and not all USB cables has the same colors.

and of course... the 12v fans will definitely run slower since the USB only supplies 5v.

gosh so complicated loool

it just about voltage and amp...

if u paired with many case fan from 1 USB port, you may end up burnt USB controller (maybe, or other power supply components on mobo) due to overheat as USB port forced to delivery more power to operate case fans...

if u dont have any experiences about electric, better buy a power adapter instead as it will cut off if wires shorted or polarity connected wrongly... just cost RM10+ only from any DIY hardware shop...

buy 12v adapter use 12v fan for better performance.

usb only giv 5v power only...its ok for lappy cooler...better use realy nipis one...

Nah.. you just need to find those fans with lower amps. exceeding 500mw. your fan either spin super slow or the motherboard cuts off the supply.

for guide in USB disecting, you can refer to here.