my phone screen is black i can't see anything also nothing is responding but, i can hear the alarm in my phone and i don't know what to do i tried evertyhing

If your screen is black or frozen

If your screen is black or frozen, you might need to force restart your device. A force restart won't erase the content on your device. You can force restart your device even if the screen is black or the buttons aren't responding. Follow these steps:

• iPad models with Face ID: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Top button until the device restarts.
• iPhone 8 or later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Side button until you see the Apple logo.
• iPhone 7, iPhone 7 Plus, and iPod touch (7th generation): Press and hold both the Side (or Top) button and the Volume Down button for at least 10 seconds, until you see the Apple logo. 
• iPad with Home button, iPhone 6s or earlier, and iPod touch (6th generation) or earlier: Press and hold both the Side (or Top) button and the Home button for at least 10 seconds, until you see the Apple logo.

If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple ...

https://support.apple.com/en-us/HT201412

You can try a forced restart of your device:--> Force restart iPhone - Apple Support

If you get no improvements, it could be a hardware failure, but we can't diagnose those issues remotely, sorry.

Make an appointment and have your device inspected at an Apple Store or AASP:--> Apple – Location Selector

Regards

Giulio

Hi.

Have you tried this?

https://support.apple.com/en-gb/HT201412