Sometimes Can't make/receive calls yet has reception
I have a customer's iPhone 6 here. Recently replaced the screen and housing for her.
Afterward, there is an issue that every so often it cannot make or receive calls (displays call failed message)
There is reception (2-3 bars), text messages don't seem to be affected nither does 3G as social media notifications still show up. Customer brought it back and I tested it with her sim card and with one of my testing sim cards and it seem to work (I could make and receive calls) serval times through out the day. However once she come to pick it up it did not work again.
Normally I would think this is an antenna issue however in this case its still display enough bars and all other functions work.
Any suggestions to test or parts to replace? (I have the phone with me currently)
Thanks in advance!
Is this a good question?