Why is my HTC Desire 826 phone screen flickering?

[AC Question]

I bought this phone around 8 months ago and it was working perfectly fine. One day I dropped it but when I used it after picking up, it was fine. Fast forward a week and my phone becomes laggy and the screen starts to flicker frequently. Also when I lock my phone, it takes multiple presses of the lock button to reset it. What exactly is wrong and what should I do besides going to the repair store?

 

[belodion]

I think it would need a visit to a repairer to find out exactly what is wrong. The best attempt at a remote diagnosis you'd get from members here could not be that.

Back up all your personal data. Let us know if you need advice about that.