It looks like it has a removable battery:
1. Disconnect the charger and battery
2. Press and hold the power button for 10 seconds
3. Reconnect battery and charger, power back on
That will perform an NVRAM reset and may get the laptop to boot up. If not, you can try also disconnecting the CMOS battery to reset the BIOS, although this will require disassembling the laptop to some degree.