Chosen Solution

I have this iphone 6 plus that was dead and I tried to restore it in recovery mode but got 4013 error a few times. Desoldered the nand and replaced it with another nand ( all the data like SN, wifi mac, bt mac,etc writen on the replacement nand from the old nand). After I soldered the “new” nand in place I managed to restore it without error, but now the phone keeps restarting every 2-3 minutes. The phone has wifi,gsm service, everything works fine in those 2-3 minutes. What do you think might be the problem?

First try with new battery or check the BSI point not contact with battery.Middle pin of the battery loose contact might be the issue.

Try another battery maybe? Check the realtime event log via 3uTools to see if that gives hints to why the phone might auto restart itself.