It happend to my ios iphone 4s as well. After upgrading to IOS 6, everything seems to be fine. Until I had only about 40% of battery that I decided to charge my phone since I was travelling the next day. I noticed after plugging the charger, I get the error "charging is not supported with this cable". I check the phone but it can do everything, make calls, send sms, everything is working fine. It just won't charge. So I decided to backup everything and put the phone in restore mode. But the phone once plugged to my macbook pro can't be detected. So I decided to save battery and turn off the phone instead. But once I powered it off, it will simply boot up back. I had no other choice to save the battery since it won't turn off.
Now the battery is dead. It won't charge (tried different chargers / tried using another laptop and usb cable / bought a car charger) none worked.
So followed the steps by CC45.
Step 1. Sleep/Wake button is functioning fine
Step 2. LCI is not activated
Step 3. Plug the iphone to it's USB charger. Almost 2 hours now. Nothing happened.
Step 4. I think I have to skip this because the phone is just dead. no signs of charging whatsoever
Step 5. While currently charging (I tried the reset) nothing happens
Step 6. When plugged to USB port. It's not detected. nothing happens. Tried it with a windows laptop. same thing.
Anymore suggestions?
I'm planning of having it charge overnight. Hopefuly like some post here, it will miraculously come back to life.