We strongly recommend servicing under expert technical supervision. Self-installation without required skills can be dangerous to the screen/device. Do not remove screen guard or warranty sticker till the complete satisfaction, screen guard removal means acceptance of the product. Warranty voided once screen guard removed. A technician can test the product easily by connecting it to the motherboard of your phone & test it fully. When you are certain that everything is working fine then your technician can install it permanently (we will be not responsible for any damage done by technician/repairman) Please keep the item in original condition and don't remove warranty sticker & screen guard.