Xperia X5 Premium Black Screen can't see anything even though Touch is working finger print working

[DanyDeaibess]

I was using my phone and suddenly i got a complete black screen. My phone was never in water or anything just was sitting and the screen turned off. 
I can hear notifications, and I can open my phone with fingerprint but I can't see anything. 
I can touch the screen and hear beeps but I have no clue what I am clicking on because I cannot see anything on the screen it is completely off. 
I read it is a software issue so I did some trouble shooting: 
1- Clicking volume up with on/off button, turning it back on again: Nothing changes. 
2- Turning off the device from the reset button near the sim card and SD card sockets: Nothing changes. 

also I tried to connect the phone to the computer which i was able to unlock by fingerprint (as i mentioned above) but I wasn't able to choose "tranfer files" option since I can't see anything on the screen. 

What can I DO?

[YoGem]

@DanyDeaibess near the sim card slot there should be small pinhole, that is used to shut off your phone. What happen if use it to turn off and restart your phone? Can you see something, like Sony's logo, or is it still black? If it's still black I doubt that it's a software issue rather than hardware. I think that you should contact your Local support to have your device inspetected.

[DanyDeaibess]

Yes as I mentioned in the post that I already tried it. I turned off from this pinhole and then turned the phone on and nothing happenes same issue. 

Black Screen, but touch is working and I can hear beeps when I click on something 

[Zenzid]

I have the same problem with my Sony XZ Premium
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