Black screen won’t restart IPhone 14

[TLD]

Hi 

my iPhone 14 screen is black & won’t restart. It went off suddenly yesterday. I managed to restart it but it went off again not long after. Charged it overnight but screen still black & no sign of it restarting. 
Any ideas? 
Thanks 

[pgn]

@TLD 

https://discussions.apple.com/thread/254226002?sortBy=rank