Sounds like the phone got a good concussion ;-{
So your logic board has either suffered a solder fracture on one or more of the solder joints or a component has failed from the shock.
This will need someone with micro soldering expertise and access to the schematics and board layout drawings. It also maybe beyond that as the complexity of this logic board layout makes it almost not repairable as you can see in the IFIXIT teardown here: [guide|98975] jump to Step 9 for more on the complexity of the logic board layout.