Won't turn on, shows black screen, and has vertical lines temporarily

Hello, my iphone 6s has been stuck on the apple logo and would’’t turn on. once powerd on it would stay on apple logo for a very long while, and then it would “turn off”, the back light would still stay on, but nothing works, including trying to hold down power and home button. However when the screen is off but back light on, itunes on my computer would recognize it when getting plugged in and out.

I took it apart like i have with many phones, and tried seeing for anything. My expectations were low, i wasnt sure what it could be. i unplugged the battery and screen, plugged them back in. when i did so, rather than an apple logo showing up, vertical lines come up on the screen and will fade away, the vertical lines are different every time. I looked on other posts and they suggested it was the connection, ive checked and provided photos, cleaned with alcohol and theres nothing. No apple logo even shows up anymore, just the lines once turned on. they will fade away, then the back light will just stay on. The computer still recognises the phone when its plugged in like normal.

Phone connectors: https://gyazo.com/75e879e0ee83719ee42ec5...

Screen Connectors: https://gyazo.com/b3c189c11a6870cac0439f...

Any help would be appreciated, thank you.