After crash my Phantom 2 vision + lost telemetry info like altitude, distance, speed, battery voltage, etc.. The info isn't visible in app, but video feed works fine.
My opinion is the problem is in wifi connection with Phantom's telemetry.

PS: After crash was one of three gimbal cables pulled out (it was four wires cable). I tested it without the cable, gimbal worked fine (What importance the cable has?).

Do you have some solving?

Those cable provide 1. Power 2. Video feed and .3 the telementry data. Check the plugs to be sure they are tight and also check each plugs pins to be sure the are making good contact.