T211 won't power on topic

Last weekend I plugged in my daughters tab 3 and let it charge and forgot about it. Last night she wanted to play on it so I took it off the charger and tried to power it on, but with no luck. I then realized the charging cable I used was faulty. The battery seems to be in good shape BC when I put the voltmeter to it, it read 3.71 volts. But I'm not sure if its charged or not. I've tried different cables and outlets with no luck on charging or powering on. I've also tried various time increments with holding the power button and or button combinations. Is there anything I can do to get it to power on? Or charge the battery without using the USB port on the tablet, I've had problems with it before and had to replace it. My daughter loves playing on it and would like to get it fixed as soon as possible.

Thanks!