iphone poor signal after a knock

[soulsucker]

sorry if this is in the wrong section but this is my first post and wasnt sure where to put it.

i have repaired a few iphones recently, new batterys ,screens etc but the other day an idiot at work thought it would be funny to punch me in the arse,which is exactly where i keep my phone :( ,

before this i could use youtube at work and generally had a good signal,i though it must be an antenna issue but having just changed it for another genuine antenna in another phone i still have the same issue so now im stumped can any one help out and tell me if theres anything else i can try before i take it to the shop and land him with the bill

any help much appreciated

[Hum]

If you open it up, you probably void any warranty.

I would look at where the ant. connects to the main circuit board.

Look for loose wires, if any.

I'm afraid tho a repair shop will be your only hope. :/