Getting a laptop to work on another display.

[Tehrealpilot]

So my old Asus laptop's display cracked, and was only displaying white. I dissembled the laptop completely, ( I am familiar with computers, and have built several of my own) and striped it down to the bare bones. After doing this I plugged in an external monitor, turned on the laptop, heard the HDD and fan spin up as usual.... but there was no picture on the screen. After several tries, I hoked the broken screen up to the laptop booted it up and the screen turned on and displayed white, so I know that the computer is functional, I just don't know how I can get it to display on the monitor. Any advice that you guys might be able to give?

 

[Tehrealpilot]

Additional details. On boot, the fan will spin for about 3 seconds, pause for about 10 seconds, and then resume spinning at full speed until I shut it off. The processor gets warm, as expected. I can't tell whether the hard drive is spinning or not. When I plug my phone into any of the usb ports, it starts charging. However when I plug my keyboard in, it is completely unresponsive. No lights or anything. I am also able to turn the computer off with the power button.

 

[SpringWater]

Why did you strip down the laptop to plug in an external monitor, were there any other issues? Did you plug the external monitor to something like a vga port or directly to the wire connected to the laptop's screen (I know it might sound dumb but it is possible to do that)? and you might have damaged some internal components when you were taking your laptop apart. My theory would be that if you completely took your laptop apart, and removed the heatsinks your cpu (or some other component) overheats right after you turn on the laptop and it automatically shuts off. I would try putting it back together and then trying to turn it on.