iphone6 flicker / stripe screen

[iMore Question]

I replaced charge port with a new one when I suspected the charging issue. Afterwards, the screen has stripes like shown in the image

(I took the picture when I just turned on the phone. The stripes were relatively static instead of rapidly flickering. Could anybody tell me what could be the problem? It is likely that I damaged the screen cable when I was replacing the charge port. Do I need to replace the screen? Or could this be due to the new charge port is incompatible with the the iphone6 model I have?
P.S. I really do not remember there exists any screen related issue when the phone was still functioning about a year ago. I stopped using it when the charging port was not working. Recently, I replaced it.

 

[anon(4697585)]

The first thing I'd do it open it back up and check all the cables are securely attached where appropriate.