My Lenovo tab s8-50lc is switching on only when it is charging,this issue occured after a system update. The very next day after the update, I was using the maps application and suddenly the screen went black and was switched off.i pressed the power button and my tab was not turning on, then I connected it to the charger and it was charging normally and was above 40% this time when I pressed the power button it turned on, but when I unplugged the charger it turned off,Now my tab is switched on only when it is connected to a charger, it is charging normally and charge is increasing also,kindly help.
Sounds like your battery needs replacing. While it may be holding some of a charge, it may not be putting out enough power to run the device.
However, before going that route, I would try starting up the tablet in "Safe Mode" and see then if it will run off the charger cord. If it does, then you have something running on the tablet that is draining the power to fast for the battery. If it doesn't stay on when in "Safe Mode" and off the charger cord, then replace the battery.
Having the same problem last week. Tab suddenly off by itself, only can boot up when charging. Tried few times of factory reset but no luck. Anyone got any ideas how to identify the root cause? Is it really related to battery?