1. Tips 1: Test before When testing, do not remove any protective film or tags. Please pay attention to the problem of static electricity. Before attempting any repair, be sure to ground yourself is an ESD (electro static discharge) strap. This will prevent static electricity from damaging the electronic components within the phone. Ensure you wear eye protection and use caution not to cut your finger with the glass splinters. 2. Tips 2: Simulates testing Screen is very fragile . We strongly suggest test before . Please simulates testing, which means mobile phone apart, (motherboard + LCD or screen) connected audio cable and new , power on, test finished. If test OK, please install it. If it can not show, at the very first time. And please do not force it to be installed in mobile phone. We will not be once the screen is installed. 3. Tips 3: Do not over-bend cable Please make sure LCD cable Do not over-bend. Over 90 degrees bent will cause black display. About the 1. front screen outer glass lens for Samsung Galaxy A90 / A80. 2. Replace the old, broken, cracked, one. 3. Make your device look more refreshing than ever. 4. 5. . 6. Professional is highly recommended. We will not be once the screen is installed.