It is always on the privacy-minded person’s mind: can I REALLY turn the microphone off on my Alexa or other Internet of Things device? The Amazon Echo Flex has a “Mute Microphone” button. Does it really do that???
The electronupdate blog finds out!
Let’s do a bit of reverse engineering to sort this question.
If one traces the signal from the push button switch it seems to flow to a small SMT part marked “ICFJ” (right most part of one’s circled below). To the left of this is a part marked “VC74” which will be a package of dual “D” flip flops and on the left the golden component is the microphone.
Decapping the chips helps find out what they are:
From here a bit more of the schematic can be teased out (simplified, some resistors not shown):
And the conclusion:
The ‘mute’ button appears to be very real and functional. When the button glows ‘red’ the power is removed from the microphones.