Take out the screen and verify the components. If it is genuine or MFI touch screen, replace it perfectly. Don’t again prefer that guy who fixed it earlier. If he can’t fix a screen, he is no a professional. DON’T pressure the screen to lock the head jack. It might get cracked.
Let your battery gets enough charge. First drain all the power in ur battery and charger it for 1 hr with the inbox adapter. Don’t use iPad’s or 12W Adapter. Then your phone will be doing fine. Don’t Panic.
That happens when (1) you have an unbranded cable. check the cable for genuine apple serial number. # Your PC or whatever connector you use to charge got some damgage, in the case if it is adapter clean the USB female gently.
Your phone will die soon back up your data After backing up rest the phone in open air for 4-5 days. Dont get curious and don’t get excited to check ur phone. forget the phone for 5 days and let it dry