If I've told you once, I've told you..............
OH,......where was I?
You post solutions.
How about posting the need information for your query?
Laptop manufacturer name, and model number.
(Bottom of laptop - Model Number)
Right off hand; A laptop that uses two cooling fans already?
I don't know if I would tax the DC - DC circuit on the laptop anymore, by adding a third fan.
Is this fan to take the place of the fried harddrive?
The extra cooling fan would use at least 3 wires.
One for Power (Positive), one for Ground, (Negative), and a Sensor wire; so the laptop (BIOS) can speed the fan up when needed, or slow it down.
Positive ( + ) power pin, can be had from the Harddrive's interface it plugs into, on the laptop.
So can a Ground pin.
Not a sensor pin for speeding up, or slowing down a fan.
The internal cooling fan of a laptop, only uses two wires.
Positive, and Negative. It is the circuit the fan is plugged into, that can determine if the fan needs to be speeded up, or slowed down.
Point is, there isn't even a sensor pin FOR the installed cooling fans, to bring a jumper wire over TO the new fan.
(Which I wouldn't recommend anyway)
The two hardware components that give off the most heat, is the Processor (CPU), and graphics chipset. (GPU)
The CPU (Processor) is usually adequately cooled in a laptop.
The graphics chipset is usually, not.
Therefore, adding more surface area, to the Cooling Tube's small metal plate; is a method to help keep the laptop cooler.
Let's use an HP Pavilion dv6000 series of Notebook PC's, Cooling Tube for an example,http://www.ebay.com/itm/HP-Pavilion-DV6449us-DV6000-Heatsink-and-Fan-431448-001-FOX3IAT8TATPC93A-/281108195757?pt=US_CPU_Fans_Heatsinks&hash=item41735aa9ad
This is actually the entire cooling system.
Fan Assembly, finned Heatsink, and copper Cooling Tube.
The large metal plate all the way to the Left, that has the X-shaped mounting 'arms' on it, sits on the Processor.
Come up towards the Right, along the Cooling Tube, and the odd shaped metal plate sits on the graphics chipset.
(To the immediate left of the black Fan Assembly)
See how small that surface area is, that sits on the GPU? (Graphics chipset)
The surface area is increased by adding a small piece of copper sheeting. (APPROXIMATELY, 1-1/4th inches by 1-1/4 inches)
Thermal Paste is put on the graphics chipset. Then small piece of copper sheet, then Thermal Paste; then Cooling Tube.
If you have twin fans, then you should have twin Cooling Tubes.
I have seen four Cooling Tubes.
Two for one fan, and two for the other fan. Two go to the Processor, and two go to the graphics chipset.
At any rate I am just rambling until I know what laptop we are talking about.
Could be a reference to a Desktop PC for all I know........