Share your experience!
After the installation of the last update 17.1.2.A.0.314 yellow stripes appeared on the borders of the screen, and sometime vibrator do not work.
device model SGP512
How to fix it?
Your best bet is to do a software repair in Pc companion.
Repair did`n help 
In that case I suppose you'll have to take it to a service center, I have no idea what could've went wrong.
It is hard to confirm the issue without seeing the screen. However please check this: Main Menu > Settings > Developer Options > Untick anything currently selected. If this does not help then I would have to advise you to speak with your local Xperia Care team regarding having a repair arranged.
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Hey. I have same problem. Seems like LCD pushed or something. On my HTC phone, after pushing screen hardly, I 've seen something similar. But my z2 is my favorite toy. I use every type of protection available. Plz, tell your story after visiting service center.