When I look through hole to take a picture, nothing is there, just black, on my Samsung galaxy mega

Unlock samsung mega 2 here
https://www.unlockninja.com/unlock-samsung+galaxy-mega-2
put your country and network update mail id, Unlock number will be sent on mail you provided

This page seems to extensively cover the topic:

Samsung SCH R960 Galaxy Mega US Cellular

android tv box stuck on a9 cortex start up screen ? - YouTube

? 0:38
https://www.youtube.com/watch?v=M1PuUl_OjOA
Feb 6, 2014 - Uploaded by wayne nottz
android mx tv box stuck on a9 cortex boot up. ... I have the same problem gets to MBOX and stays there ...

How to factory reset the U-M8 TV box, How to restore your ...

? 4:59
https://www.youtube.com/watch?v=cHuPeWU2cTA
Dec 14, 2014 - Uploaded by EntertainmentBox
I will show you how to use the android system first and also how to reset with pin in ... ... factory reset M8 but ...

stuck on m8 box logo - FreakTab.com

Samsung is coming out with a new Galaxy s6

If you've meant "to switch off WiFi and use LTE" then just go to Settings and turn it off. The term APN (Access Point Name) refers to old GPRS protocol.

Try taking the back off and dabbing away any moister in each half. Then use a hair dryer to dry the unit thoroughly, leave open for about 15 minutes then replace back and try charging again.

on windows pc: log into play.google.com
check your devices... and the galaxy mega should be there if not please add it. then you WILL be able to sync any of the google apps. this is the only way.

good luck.

is it Samsung galaxy mega or lg optimus

as qustion detailed

for samsung galaxy mega

for lg optimus l9

Do you mean the network unlock?For this you need not root the phone.instead approach Simpleunlocking.com and specify the model, country, locked network of Samsung Mega 600.Based on the availability you can get the unlock code along with free instructions.
http://www.simpleunlocking.com/samsung/rs16wp8/