My SO's Nexus 9 stopped charging recently. She left her charger for it at her parents, and when they stopped by to drop it off, they gave her the wrong one. She was using the new charger for a few weeks, and while it charged slower, it worked, however it recently stopped charging or recognizing that it was plugged in. She's tried different outlets, and I believe a few other chargers that fit, but to no avail. She said when she plugged it into her computer while it still had some battery, it wouldn't charge but the tablet recognized it was connected to a computer. Now the battery is fully dead. She has it turned off and plugged into the wall charger, but the charging battery symbol you get when the device is off does not show up. If she holds the power button, the device does a brief vibration, but nothing else happens. Does anyone know how to fix this?

Edit: Current charger being used is 5V and .7A