Poor cell data signal after charging connector changed
I took my iPhone 6 in for a charging port replacement as it was not charging. They replaced the charging dock assembly but when I got it back, the cellular phone and 3G data signal is substantially poorer than before. I do not get signal at all in places I used to get fine signal, and other places I got great signal I get very poor signal. I have lived and worked in the same area for 3 months and had consistent signal every day without change, only now after this repair it is suddenly substantially worse.
I took it back to the shop and explained but they washed their hands of it and said there was no issue.
On the iPhone 4 there were a number of metal tags that connected the cell antennae and if these weren't connected fully it could degrade signal.
What can I check on the iPhone 6 that could be responsible for degraded signal? I do get some signal in some places but it is much worse than before and it is definitely since they replaced the charging dock.