Chosen Solution
If i buy a bare motherboard to replace on my iphone do i need to buy chips? Or do i just replace like that.
A bare board (they usually cost a few dollars) has nothing on it; it is absolutely bare. I would add that there’s no guarantee that the board has full integrity of the inner connections. An iPhone pcb has ~10 layers, you can only see the top and bottom. Any broken or damaged inner trace will render it inoperable and almost certainly unfixable. As for populating it successfully yourself, it is about as close to impossible as you can get. You could migrate as many IC’s from your dead board as possible but you don’t know which ones are good and which ones aren’t. You would have to source hundreds of components, many of which are custom designed by or for Apple. There are also several IC’s that are keyed together…they have to come as a set. The CPU is a dual layer IC that has ~1000 tiny “solder balls” as connections point under a 1 square inch chip. It would certainly be a fun, educational project to undertake if you have the proper tools and skills but it would likely never work and end up costing you way more than if you just bought a used but functional (not locked) logic board.
Do not attempt to replace iPhone 7 board. It costs you more than official repair and you end up with a junk phone. In- place repairs are feasible.
The most feasible thing to do here is fix your original logic board–what makes you think it is “fried”? When was it last working and what happened since then?
I have a iPhone 7 Plus used contactless then my phone froze I did a hard reset the phone hasn’t come back on tried new battery and new screen still nothing any help
