MSI GT640 User Manual page 34

2-13
7. Power Button / Power LED
8. Stereo Speakers
Give high quality sound blaster with stereo system and Hi-Fi function supported.
9. Internal Microphone
There is built-in microphone and its function is the same with microphone.
Power Button：Press the power button to turn the notebook power
ON and OFF.
Power LED: Glowing blue when the notebook power is turned on.