Mipad 4 with blackscreen, background light when boot up.

Hi.
My mipad screen can't show anything only black but illuminated when it booting up. I tried to flash with miflash but no work. There are sounds and led when battery charging. ADB is working
Is this a hardware error? if yes which part of hardware should I repair?
Thank you for your time
Edit: I’ve never dropped the phone nor has the phone been touched with water, I also have a screen protector on and smart cover