Please follow the following steps:
1. Remove your tablet's cover.
2. Disconnect the cable (2x red, 2x black and 2x yellow) at the middle of the tab which connects the battery with the motherboard (For 10 minutes). Then reconnect it.
3. Disconnect the cable joining motherboard and tab screen.
4. Charge your tab with USB charger for 20 minutes to 2 hrs. (It depends!)
5. Reconnect the cable joining motherboard and tab screen.
6. Turn on your device using power on/off button.
Maybe you're good to go now!