Internal display wont turn on. External display works.

Hello, after a successful WiFi card replacement the monitor wont turn on. I disassembled the Macbook, exchanged the HannStar Airport module for a BroadCom one and it works but the display wont turn on.

I plugged in an HDMI adapter to the Mini Display Port and from it to an external monitor and it works. I removed the cover and cleaned the connector , reseated it, inspected for debris, cleaned with compressed air, cleaned connector with Alcohol and it still wont work.

On harsh light I cant see anything (no backlit damage) and on the "About this Mac" the only monitor registered in the display/graphic card is the external one (just like when the Airport card go bust it stops to show in the About this mac).

Are there any other troubleshooting steps to make sure it's a busted LCD panel? Im typing this from the macbook connected to the external monitor.

Thanks for any tips!!