iPhone5s screen is flickering. I am Capable of micro soldering.

Hi. I literally have an iPhone 5s from !&&*. It’s my sister’s. It was having issues with recognizing chargers. I replaced Tristar after trying known good housing. It fixed it…for a time. Apparently,since I god aggravated at the dock fpc connector,I pushed a bit hard. It wore it down. I used hot air and replaced it. I put a quarter on the baseband and all shields were on.(the back shield I put back on after Tristar with my soldering iron ,no hot air.)

Well,it stopped charging. Apparently my soldering iron caused the stupid charging battery mosfet with 4 balls to lift off(wtf)? I’ve never had this happen on another 5s. I rebelled and put it on. It charged again,yay! Well,now the screen flickers!! I’ve tried multiple screens. I’ve had this happen before when I was new to soldering and practicing on a eBay 5s. How the !&&* is this possible? It’s so weird. I don’t know how I could’ve possibly gotten enough heat to effect the backlight drivers. I use a quick 861 dw on 30 airflow(pretty low),and 385 c. The charging mosfet went on within a normal amount of time(like Jessa Jones or etc.

im floored. I’m getting close to snapping the board. This is so annoying. How can I have this much bad luck? I’m not overusing hot air. I use a coin on sensitive spots. I’m quick. I use leaded solder. 

I never used hot air to put the back shield back on. I used my iron with my smallest bevel! 

Anyone have any helpful info? I need accurate information please. 

Thanks