I too had issues with front and back camera for IPhone 4S.
I have been trying to reach Apple Support since Friday...long hold. Finally I was able to get thru early this AM.
The Apple guy had me do these steps (yes took notes so I could share with others):
*The following instructions are to test Data Errors if they occured*
Plug the phone into computer - open ITunes.
Right click on "your phone" in ITunes menu and "Create a Backup"
Unplug phone from computer.
On the Phone itself - (make sure you are disconnected from ITunes)
Select: Settings, General, Reset, Erase ALL Content and Settings
This will wipe EVERYTHING from the phone - (does NOT restore to factory, more on this later)
Turn the phone off - via holding the Power button then and Home Button (being specific for non-techy folks)
Leave phone off 5 minutes
Turn phone on - do NOT connect to ITunes yet
You will be back to square one at this point.
Go thru the steps of setting your phone up, but when you get to the "Do you want to use ICloud/ITunes" window - DO NOT sign in with your AppleID - select SKIP at bottom right corner.
Continue until you see the home screen which will NOT contain ANY of your Apps, Contacts, etc.
Now....double click the HOME button
this will pull up a small window at the bottom - this is called the Multi Tasking Window
You will see Camera App (and maybe a few others) in this window.
Press and Hold the App until a - (minus) sign appears. Click on - (minus) sign to remove ALL Apps from Multi-Tasking Window
Hit the Home Button and now try to open the Camera App from the Home Screen
If your camera works, then it was a data error and you should be able to then connect back to ITunes and restore all your Apps, Contacts, etc and be good to go.
These instructions were to fix problems with the Camera if it was a Data Error.
This did NOT fix my problem so we went one step further to test Firmware Errors.
So with the phone still not containing ANY of my Apps, Contacts, etc
Plug phone into Computer and open ITunes
DO NOT LET THE PHONE Sync with old Apps, Contacts, etc
On the Summary Page select "Restore"
This will wipe EVERYTHING - and restore back to the factory - data and firmware wiped!
This is a different restore than doing it directly from the phone "Settings, General, etc" that was mentioned above.
Once the phone is wiped, while still plugged into ITunes, "Setup as a New Phone" and make sure you name it something different than your "old phone name". Do this from ITunes - NOT from the phone itself.
Make sure you do NOT sync ANYTHING!
Let ITunes do the New Phone setup stuff and when done, while the phone is still plugged into ITunes, open the Phone and go thru the steps of setting your phone up.
When you get to the "Do you want to use ICloud/ITunes" window - DO NOT sign in with your AppleID - select SKIP at bottom right corner.
Continue until you see the home screen which will NOT contain ANY of your Apps, Contacts, etc.
Now....double click the HOME button
this will pull up a small window at the bottom - this is called the Multi Tasking Window
You will see Camera App (and maybe a few others) in this window.
Press and Hold the App until a - (minus) sign appears. Click on - (minus) sign to remove ALL Apps from Multi-Tasking Window
Hit the Home Button and now try to open the Camera App from the Home Screen
If your camera works, then it was a firmware error and you should be able to restore all your Apps, Contacts, etc and be good to go.
This did NOT fix my problem either and so here is where it gets fun!
If you were like me, thru my "Service Provider - AT&T," I was eligible for an upgrade. So I ordered and received my phone, had it less than 24 hours, and the "functions" did not work.
At no point did anyone from AT&T mention that Apple requires you to purchase AppleCare+ protection plan to get help. Note, I put a ➕ sign because it's different than regular AppleCare. Make note of this and see further details here (http://www.pcmag.com/article2/0,2817,2394635,00.asp#fbid=PgMDz9m_gBy).
The Apple Support guy told me I had three options:
1. Pay $30 and Apple would ship me a new phone - in return I send the old phone back
2. Return the phone, they would repair, and send it back (no I dont get a loaner during this time)
3. Hunt down an Apple Store and see if they have any extra to "swap" me out
The Apple Support Guy told me these were my only options. I pay them, send phone back and get it returned "refurbished," or pray Apple Store can help. Told me that "well the phone works, just the camera "feature" doesn't. How do you purchase a $700 product and tell your consumer, well its brand new, the "phone" part works, it's a phone, what else do you expect? - I Didn't just order a Phone!!
Your blood boiling yet? At this point I asked to speak to a Supervisor.
While on hold, I went one step further - KNOW Your Warranty RIGHTS and Apple's Legal Disclaimers. Thats right - go check this out: http://www.apple.com/legal/warranty/iphone/ They don't have a Legal Disclaimer for 4S! However, that doesn't really matter unless you plan to sue at this point, but it does outline the other One Year Warranties. Nowhere does it state on their website, in their Warranty Policies, Terms & Conditions, nor any documentation that was received with the new phone that they can deny nor charge you for "Getting What You Paid For"!
If you bought a car, drove it off the lot, the windows didn't work and the dealership told you the windows can be manually lifted up and down, they didn't serve the purpose of "transportation" would you take it sitting down if they told you you had to pay $1 to get a car that worked with features they sold?
So after I got a Supervisor, we went thru ALL the steps mentioned above AGAIN. He tried to tell me that if I didn't purchase the AppleCare+ that I was subject to the 3 options mentioned above. Well, after I shared with him the Legal research I did above and nowhere did Apple send any documentation with the Phone that I HAD to purchase the care, etc., he changed his mind. I now have a Replacement Phone being shipped within 48 hours at no charge to me!
If you purchase ANY product - Apple, Dell, HP, Ford, Chevy, Maytag....I can keep going - KNOW your rights as a consumer. If it came from the Mfg Defective and the Mfg has agreed it is defective - YOU SHOULD NOT BE CHARGED to GET WHAT YOU PAID FOR!
Now Apple Supervisor made it right - but not after a lengthy process.
GOOD LUCK folks - hope its just Data or Firmware problem you are having