SOLVED: Rear microphone of the HDA Intel chip (Realtek ALC887) does not work in Ubuntu

My computer has the MSI H81i mainboard, which features the  HDA Intel chip (Realtek ALC887).

In Ubuntu 15.10 or 16.04, the rear microphone jack does not work by default.

Also, the rear blue jack works as line-out in windows, but does not work in Ubuntu.

I fixed it by these easy steps:

Rear line out

Just run:

alsamixer

and set the mode to "6 channels"...

Rear microphone

sudo bash

apt-get install alsa-tools-gui

hdajackretask

Then, in the GUI select this:

hdajackretask: the GUI for overriding audio jacks

The click "Install boot override" and reboot...