Screen dims and unresponsive, horizontal and vertical lines
It is most likely a problem with the display/display cables; which requires a screen replacement. If you still have a warranty on the phone, then you should bring it to an Apple Store. If you don't have warranty on your iPhone, I can help! I have an online computer and phone repair shop/store. If you want to mail me your phone for a repair; I'd estimate it to be around $50. Please email me with any questions.