Help Help with black screen

[LoPCY7]

Hello,
A friend of mine has a Samsung Galaxy S4 Mini.
Her phone has the follwing problem:
The screen turns off randomly, even though touch commands are still working.
Also, some times the phone may turn on and you can hear the sound, you can see the light at the touch buttons, but the screen stays black (however if you touch it, you can understand that the touch functions are still working).

I have tried removing and reinsterting the cables, cleaning everything with alcohol, factory reset but the problem is still there.

Do you have anything to recommend?

Thank you

 

[BubzzLemz]

Has the phone ever been exposed to water or anything getting in it? Sounds like the screen might need a total replacement since you tried everything else. Screen replacements are rather cheap and reasonable if you or someone you know can do it when you get the parts online. Also, has the phone been overcharged even when it reaches 100% charge? Sometimes an overheated battery can short and cause phones malfunctions. I only say that from experience. Good luck.