No signal after dock replacement

Hey Guys,

I've got a customer who attempted to change the dock on his iPhone 4, and now he is receiving no signal.

I've made sure that the 'WIFI/Reception/speaker housing' cable is firmly attached to the motherboard, however that didn't change anything. I changed the dock, and also changed the speaker housing, but this still hasn't affected the no signal fault. I then disassembled the whole phone, made sure the customer hadn't accidentially damaged any connecters (which would be hard to do with a mere dock assembly replacement, nevertheless..)

Abit baffled, because nothing seems to be at fault. I haven't restored the device yet, but perhaps this wouldbe the next step.

Any tips or advice would be great.

Cheers!