Display errors after installing lumia cyan

[WPCentral Question]

Hi, I have Lumia 820 and I recently updated to Lumia Cyan. Since then, I've been experiencing difficulties with the display after watching a video (YouTube or elsewhere). It happens randomly,not always when watching a video. At first the screen freezes and you can't do anything with it. Then the screen turns off. If I try to restart the phone by holding lock button, the screen turns off and suddenly it goes all grey with stripes. It happened to me twice and I managed to restart the phone and everything went fine. Today it happened again, but I can't do anything with it. The screen changes from black to grey with stripes and nothing helps.
I think that it might be a bug coming with the Windows 8.1. update. Is somebody else experiencing this kind of problem?
Thanks

 

[Muessig]

I've had a similar issue myself but the only way I have been able to get rid of it for good is to reset my phone. First I'd try a soft reset, which you can do by pressing the volume down and power button simultaneously for 10-15 seconds or until you feel a vibration. This is like a factory reset for your phone but you keep all of your personal data.