Press and hold the power button for about 6 seconds. If the power light continues to flash, disconnect the AC mains adapter and then remove the battery. Reconnect the AC mains adapter and press the power button. If the laptop works, shut it down and disconnect the AC mains adapter, install the battery, and reconnect the mains adapter and press the power button. If the power light flashes but the laptop does not turn on, you may have a defective battery. You can try to let the battery charge for at least 20 minutes to see if the light stops flashing and stays on steady. If these steps don't work, let me know and i will try to help further.