The other day my T-Mobile Galaxy Note 2 ended up in a “Factory Mode” with Phone, CSC, PDA, and various other things displaying over the home screen in yellow characters with a box. Well, it was really annoying but there’s a quick fix for it.
You will first need a rooted phone and edit the file using ES File Explorer or Root Explorer.
Open the file “factorymode” in /efs/FactoryApp directory, it probably says OFF. Change it to ON then reboot your phone.
Also, you can use adb shell to do this too:
echo -n ON > /efs/FactoryApp/factorymode