****READ THIS!!!****
Hey guys! So I was having the same exact problem and I kept reading through these threads only to find people telling me to do what I had already done about a thousand times with no luck: Try a hard reset, try reestablishing network connections, try a factory reset, etc.. It was so, so frustrating!
I decided to go to the Apple Store and the guys at the genius bar gave me a new phone since I was under warranty. HOWEVER, GPS stopped working on my one-day-old phone! So the next day I went back, and they ran tests, switched out my sim card, tried another factory reset, etc. to find that my GPS just wouldn't work. So they decided to give me ANOTHER new phone. And guess what? The next day GPS stopped working on my SECOND NEW PHONE! Just imagine how frustrated I was.
So I actually decided to take my phone to the engineers at the company I work for, and they asked me the simplest of questions: Have you tried using GPS without the case? (I had this little metal bumper case)
OMG...... It worked!!!!!!! Apparently, there was a metal part (I suppose) that was jamming the GPS' signal.
SO YOU GUYS, BEFORE YOU SPEND ANY MONEY, TRY USING GPS WITHOUT THE PHONE CASE!!!!!!!!!
I HOPEEEEE THIS HELPS SOMEONE.