Why is my iPhone screen & sound broken but connects to iTunes?

I've got my old iPhone 5c with a black display, no vibrations and no speaker/earphone functionality. However, when I plug the phone into iTunes the phone appears as normal and allows me to sync with it etc.

This issue persists despite a restore - the phone is cracked which would lead me to believe the LCD is broken however the fact the vibrator and sound doesn't work when calling the phone or plugging in the charger leaves me to believe this is a more complex issue. Is it possible there is a fault with the logic board or a drop to the phone caused multiple connectors to come loose? I'm really puzzled here.

Cheers.