Just replaced my laptop screen, screen is black?

[gaspiden]

Well my laptop screen broke about 3 months ago and I've been using an external monitor ever since. Just now, I finally got a replacement screen for my laptop. Anyways, Initially when I was using the external monitor, the screen on the laptop would be glowing as well. Then after a while I believe it stopped. When I replaced my laptop screen (I followed the procedure correctly from a video on youtube), the screen was black even though the laptop was on and functioning. I then connected it back to my external monitor and it was still working fine.I then took the screen a part again, made sure I connected the video cable properly and tried it again. Didn't work. I tried taking out the battery and power cable, holding down the power button for a minute, and turning it back on 3 times. Didn't work. I then took out my ram cards, left them out for a while, then but them back in (changing their slots) and it still didn't work. I then ran a windows memory diagnostic to see if there was any problem with the ram, and it reported no problems whatsoever.

I'm really out of options here and have no idea what's causing the problem. There is no inverter since it's an LED screen. I also put a flashlight on it and there is no image on the screen when the laptop is turned on. My best guess is that there's something faulty with the connection from display to the laptop (whether it's the cable or some connector) since the computer doesn't detect any built in display.

I'm stumped. Suggestions are much appreciated.

 

[Dhamilton]

Use the "Fn" key in combo with the Screen key ( without knowing your laptop model# thats the best I can say).
Do this while your laptop is connected to the external display.
It should switch the output to the laptop.
If it does not, then consider that
1) the screen was not installed properly/connector is not inserted all the way
2) the cutoff switch for the screen is stuck in the Off position ( this is often found near or on the hinges)
3) the screen is defective and needs to be RMAed

 

[gaspiden]

Use the "Fn" key in combo with the Screen key ( without knowing your laptop model# thats the best I can say).
Do this while your laptop is connected to the external display.
It should switch the output to the laptop.
If it does not, then consider that
1) the screen was not installed properly/connector is not inserted all the way
2) the cutoff switch for the screen is stuck in the Off position ( this is often found near or on the hinges)
3) the screen is defective and needs to be RMAed

Thanks for the advice. I believe it might be the cutoff switch. I dissembled the laptop to the motherboard and took out the hinge covers. I still can't find any sign of a cutoff switch. The model is a HP Pavilion G6 with an AMD 3400M APU. Any idea as to what it might look like?