My phone screen turned back but its still on?

I was watching YouTube on my Google pixel 4xl suddenly screen turned black but the video was playing in my airpods... I tried restarting it many times but no luck... I thought my phone screen was dead....I went to repair shop they says its not the display but the problem is in display ic chip.... So I ask a question is these any display Ic chip in Google pixel 4xl... would a phone functions same as before when opening the circuit and changing the ic stuffs...

Need urgent suggestions thank you...!