@danj This exactly. If you have a fan spinning, connect an external display. Also, disconnect the battery, then plug the MBA in; the computer should turn on by itself. If it does not turn on by itself, use the power on jumper pads on the board to try to turn it on.

Your screen compatibility is: MacBook Pro 15" Retina (A1398) Late 2013 to Mid 2014

Your display assembly compatibility is: MacBook Pro 13" Unibody (A1278) Early 2011 to Late 2011

Number 2 in your picture is the LVDS cable. Damage to that cable can cause the backlight and/or entire display not to work. The other issue could be a blown backlight fuse or something of that nature. I would start with an LVDS cable as they’re relatively inexpensive.

Did you accidentally enable “Mouse Keys”? Here’s a link of what I’m referring to: https://www.idownloadblog.com/2017/01/23...-to-move-and-control-mouse-pointer-using-your-macs-keyboard/

I would start with connecting an external display and seeing if you get image that way. If you get display, shut down the computer, then check the LVDS cable where it slides into the socket on the board. If the pins are damaged, you could try replacing the LVDS cable. Also connect the display and power the computer on. Use a bright light and shine it on the screen to see if you can see a faint image on the screen.