I m using i6 . I’m having problem in updating iOS to 9.2 . Every time I open settings to update it shows "checking for update.* " and then "unable to check for update( an error occured while checking for a software update) ". on researching several times atleast I have contacted the apple supprt and they hve resolved my problem my first advise is that if the phone is un watrenty period you whoild contact the brand to fix it tgey will help you a lot to solve the issues and trouble shoot you all online