What part of the iPhone 4 hardware gives the SERVICE?
I would like to know what part of the iPhone 4 hardware gives the signal (service) to the mobile.
I had to replace the LCD Screen due to it got broken, I followed the steps from this webpage but when I turn the cellphone on, No Service comes up (no signal from my company) ..
What can I do?
You may have accidentally damaged or not reconnected the antenna. I have fixed hundreds of iPhone and have come across this issue many times. Please check the small pop connector that is near to the battery connector( where the battery connects to). If you are still having issues locating the antenna please refer to there guide that talks about replacing a antenna. Link will be below. I hope i helped and have a great day.