Make sure the following is in the retail package when checking your box and phone

a) *#92702689# = LIFETIMER MAKE SURE ITS 000000:00
b) *#06# = PHONE IMEI MAKE SURE ITS THE SAME WITH THE BOX
c) *#0000# = FIRMWARE MAKE SURE ITS UP TO DATE
d) Check the screen for dead pixel by changing the screen to 1 colour.
e) Check for any physical or tempted damage on the phone body