iPhone 4 No Service After Repair

Hi, I recently replaced a speaker on my friends iPhone 4. When I switched it on it is constantly 'Searching' or 'No Service'. The antenna connector is in securely, all the screws are in, and the contact clips etc. The blue inductor however is missing so I have soldered the two contacts. But.. Still no signal. Any suggestions are vey much appreciated!

Ps I have replaced the antenna 3 times but still no luck. iPhone is on iOS 6 and I have reset the carriers settings, manually set the time and tried removing and inserting the sim.