Phone went inside a water bucket but after that it's stuck in bootloop

Hey there,

Hope you're doing well. Actually 2 days back my phone falls inside a water bucket but I keep it out in just a sec. I don't remember actually but it was not opening. I did a little mistake that I didn't keep it in the sun. It went on after sometimes but the speaker was not working. It went again off so I tried to keep it inside rice (not my ideaa) but it came back to life and even I was able to call a friend.

Everything was going great but suddenly the phone's screen blinks and bam it was not able to completely booting. I tried to take it to some shop but that doesn't work.

They are saying that the motherboard went off but I don't believe into this because the phone is able to show the battery charging and all. Also I'm able to open the bios and all the functionalities.