B737NG O2 system
Years ago, possibly B732 or B733, I was told, and read somewhere, that after use of the O2 mask it was necessary to turn off the O2 from the mask by closing the stowage left door and activating the test slide/button. I was also told that when the mask was out of the stowage the mic was automatically transferred from boom to mask, and it was necessary to perform the O2 off procedure to transfer the mic back to boom after usage.
Now I search the NG Vol 2 and can find no mention of this procedure. The O2 system looks the same as earlier models. Can anyone enlighten me with 100% facts?