Bugs & Problems in Android 4.4.2 update for Grand 2 Duos (SM-G7102)
◾Random Reboots
◾Entire screen Turning Red/Blue/Purple
◾Soft Key Light’s not working
◾Not able to connect to Wifi Networks
◾Dual SIM Network Failure
◾Power & Lock Keys not responding
◾Longer Charging times
◾Poor Battery Life
◾Not able to change Lock Screen/Home Screen Wallpapers

ที่มา http://www.justaboutphones.com/samsung-galaxy-grand-2-duos-android-4-4-2-update-issues/