iPhone 11 Pro Max randomly stopped working- help!

out of warranty-

My iPhone 11 Pro Max stopped working last night. First the screen started flickering and then it just went dead, I was just browsing Twitter when it happened. I’ve never dropped it in water or opened it or done any mods to it. I’ve never done anything that would have caused this. I only use Apple chargers, I’ve never dropped my phone, etc, this was completely random. It is about 2 years old, so it is out of warranty. I also don’t have Apple care. I’m pretty sure the logic board is fried, because it has no sound or vibration or anything, it’s completely lifeless, and I’ve tried every trouble shooting method you can think of. If I bring it to Apple, and the logic board is in fact fried, would they replace it out of warranty because of a defect? Or would I have to buy a new phone in full? I’m not sure how their policies work so could someone clarify. Also, what would you guys do if you were in my situation? I’m 16 and work at McDonald’s and I can’t afford to pay any more than 600$ (cad) right now.