I am writing this review in order to help some one with the same situation:I had issues with the battery "battery is not detected" flashing red light, I fixed follow below steps (I'm an IT Engineer) so I have experience with this situations.* Turn the laptop off* Disconnect the AC adapter from the laptop* Remove the battery from the laptop* Press and hold down the laptop power button for 10 seconds* Reconnect ONLY the AC adapter to the laptop, no battery* Press the laptop power button- If the laptop powers on, the AC adapter and power port are functioning- If the laptop does not power on, either the AC adapter is faulty or the power port is faulty* If the laptop powered on in the previous test, turn the laptop off* Disconnect the AC adapter from the laptop* Press and hold down the laptop power button for 10 seconds* Reinstall the battery into the laptop* Reconnect the AC adapter to the laptop* Press the laptop power button- If the laptop does not power on, the battery is faulty