If anyone is still using the dino-aged iphone 5s like me ;) , please follow the steps rather than the video patiently before putting it into action. The screw placement is extremely crucial during reassemble. I messed the screws up the first time and had problems with touch screen, it wasn’t working. Then I disassembled again. I was lucky to have sufficient eyesight to figure out the 1.7 mm screws - both magnetic and non-magnetic ones. In case of of lower left screw, I put the one I felt (!) the bigger one, and at the end, left the lower right hole unscrewed. It’s working fine now.