Hello,it is a flex problem that mainly occurs to flip phones as a result of various opening and closing of the flip.all you need to get is a new flex to fix up the faulty one.you can kindly take it to an authorized expert to fix it up for you if you are not electronically inclined.and also it could be a affect the inner screen soonest if not attended to immediately.it could also be that the outer screen is bad so after the flex is replaced if the screen still does the same then you will need to fix up the screen.
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take care.