Hi all helpers, i found the solution as WiFi address and Bluetooth address are more important than all of the rest information(as new phones have so many serial numbers) so so I found a service I can retrieve the Bluetooth address and WiFi address from the serial number and imei number. so for your information if it happens there is a solution for it.
1 there may be something(fluff) stick inside. Try to clean it with the toothpick as they are safer than any metal pointy thing. And clean it out the dust, fluff 2 if that won’t fix the issue you ll have to change the charging port flex cable
Something is probably shorted to ground in the phone that’s why it’s pesosting the issue. Or battery might be faulty itself. It doesn’t matter it’s been done by Apple or thirst party. After all Apple will deny lot of mistake they have done in iPhone 7 design. It’s a deep debate. In your case(the phone can be repaired and problem can be solved, but because you used Apple authorised repair centre that’s why you shouldn’t go to third party repairs. Instead go to Apple store and explain them the problem started after the work has been done on the phone. I think you ll be get it sorted.
Why have you changed your phones battery? number of possibilities 1 the battery you have bought might be dead and needed activation or faulty battery 2 tristar(u2 or charging ic) might be faulty and won’t charge up dead battery, in this case try to use charges battery and see if it works. If you have tools you can Test you tristar. or activate the battery with battery activator or power supply.
It could be hardware but most probably it’s software. The best suggestion is start with full restore with iTunes. But make sure you backup your phone as you don’t want to lose any of your data. let me know if doesn’t work
Just recalling the nand will not sort the problem. Nand memory chip is currupted. You need to remove the nand clean it reprogram it and solder it back on but you need to be very careful on desoldering and soldering the nand on 5s.5c etc. because there is CPU ither side of the nand and the cpu can be overheated very easily. so you need to be very careful. if you don’t have nand reprogramer remove it and I ll reprogram it for you.
No the original button came with the phone is paired to the board with encrypted code. so even if you change it with another gannuin (EDIT - genuine) button, still it won’t come back. But you can get the broken button repaired.
sometime when you don’t connect battery properly, it can be on boot loop. Connect the battery and disconnect the charger and try it to turn on if it’s on bootloop than there is issue with the board. if it wouldn’t show anything than plug the charger if it’s only on bootloop while just connect the charger and the battery it means either your battery is not connected properly or it’s damaged. because if you connect just the charger without battery it shows bootloop and the phone try to turn on but because battery is not giving it’s A that’s why it’s not turning on.