Try putting your time and clock on manual and put in the right date and time and this might help you out it has for me so many times as its always the small silly things,? Good luck
When screens are replaced and the battery is unplugged then the clock and date resets to 1970 (dont ask lol) but if you tryed all others and sometimes its all down to going on the clock time change the time and date and that will get your service back but i only know this works with the iphone so good luck,
The only way is a hard reset on an android and on iphone you will have to plug into itunes and put the iphone in dfu mode 1st then restore the phone but you got to remember that you will lose everything on the phone but if you have an iphone and you had siri switched on look on youtube on how to bypass the passcode and it will show you step by step, goodluck
Take the battery off your laptop and put on power and see if it works then and if it does its the battery as mine was the same and mine was a brand new battery, ? Good luck
Always practice on a broken logicboard as when i 1st started i had a cheap air gun and cheap soldering gun and i ended up burning off the pads behind the chip connectors and that was down to the heat so i got all the proper equipment then practiced on a smd diy clock that i built then onto broken logicboards and now im loving it but its all down to practice, good luck