Hi,
Same problem with my brother's MBA. I disconnected the camera connector ([guide|6361|step 12 of this guide|stepid=27448])
It then started seamlessly. I reconnected the camera connector: it started too :)
I then performed a SMC + PRAM reset and it seems working for now.
So good news: it may not be necessary to change the LCD assembly, just disconnect camera, boot, turn off and reconnect camera.