Android black screen of death sony xz premium

[KKM3_7]

I have been using sony xz premium USA version unlocked for the last two years. Today for the first time I have faced an issue called android black screen of death while on the call. I don't know the cause of problem. I would like to know possible reason for the Android black screen of death and possibly how to avoid the issue. Sony has stopped security patches and os updates. If at all there is an issue with firmware how to correct that with out loosing any data on my phone.. Thank you 

[magafupi]

hello. did it happen once? try to reproduce the error. otherwise it will be difficult to understand what the problem is.

[KKM3_7]

Black screen of death happened once but while using amazon prime video the phone is getting hanged and rebooted multiple times. I am unable to uninstall the Amazon video application from mobile too. 

[Zenzid]

I have a similar problem with my Sony XZ Premium.
My Sony XZ Premium screen has gone black, I can hear the phone beep when I touch the screen 
after startup, it vibrates and I have tried pressing the buttons simultaneously in different combinations and all the rest but the screen remains black. 
I cannot find any solutions and cannot find out if replacing the screen will fix the problem. 
replacing the screen will cost around 200 USD or 200 Euros, so I will not do it if it has no effect or the screen is not the problem. Without any solution I will have to stop buying SONY products and stop recommending them.  I find it hard to believe that SONY themselves do not know what the fault is, and which component is flawed/faulty and cannot understand why they are unwilling to provide more detailed information on the fault and a proper solution to fix their own product. The Premium line is not an inexpensive piece of technology and we do not pay for top of the line models to end up with close to zero support or advice. 
Sincerely