The charge indicator does not appear.

Make sure you have securely connected the tablet with the USB cable for Multi Port, the USB cable for Multi Port with the AC adapter, the AC adapter with the AC power cord (mains lead), and the AC power cord (mains lead) with an AC outlet (wall socket).

Your tablet does not support charging the battery via USB connection from a computer or a commercially available charger not designated by Sony. Charge the battery using the supplied AC adapter or designated Sony AC adapter.