iPhone 5S Front Camera Not Working After Upgrading to latest iOS (10.2.1)

Greetings,

I have the iPhone 5S 64GB. For weeks I kept refusing to update from 9.3.5 to the current version as I liked the old one better. A week before I decided to update, I changed my battery. There were no complications, the phone worked exactly as it used to except with a new battery. I checked everything, it was all fine.

So a week later I finally threw in the towel and updated my software to the latest iOS 10.2.1 and my PC also has the up-to-date iTunes software.

A day or two after I updated, I attempted to use my front camera to take a picture of myself, and the viewfinder (what the camera should see) was black yet all of the camera options were still available (such as choosing video, photo, square, etc.) If I try to take a picture or video nothing happens. I can keep clicking the capture button but nothing saves to my camera roll. This happens whether I try it from the lock screen or through the normal home screen.

My friend had the same problem and for some reason he decided to get a new iPhone, to me that seems like a waste of money.

Anyway, I've been Googling everywhere trying to find a solution. Some users have had the same issue or a similar issue but nothing has been resolved.

What I've tried:

- Factory reset of iPhone (setting up a new phone)

- Restoring from a two backups (one I had from 9.3.5 which I had to download an old ISPW and another from before I did the factory reset)

- Turning the phone on and off

- Doing a hard restart (home+power)

- Cleaning the phone screen and the front camera

- Restarting PC before and after backup

- Trying on a different PC

- Trying with a different USB cable

So since nothing has worked and since I can't find any solutions, I thought I'd make a post hoping someone can help me. This is a big issue to me since I now can't Facetime or Snapchat.

Thanks in advance,

Nick