Want to Find DC Power Connections on Compaq C700 Laptop

I have a Compaq C700 laptop that overheats. The OS I'm running takes over the control of the fan from BIOS.  The fan just cycles on and off, turning on at 100% capacity for a few seconds once every minute or two. 
This is not enough cooling for the processor and it is getting burning hot... hot enough to cause logic faults and make the computer crash.
I need to locate a DC power bus/connection that is live when the computer's power is turned on inside the machine, but that goes dead when the computer is turned off.  For instance, a USB port, the motherboard's DC supply, or the DC supply of the LCD would all work.  
Can anyone show me where one of these points would be that I can use to hard-wire my fan to, so the fan runs all the time the computer is on?  
Thank you,
Sean