HDA Intel PCH device randomly not detected

I am having a similar problem as Kevin Lee
https://answers.launchpad.net/ubuntu/+source/alsa-driver/+question/284240

My system has:
Codec: Conexant CX20753/4
Codec: Intel Skylake HDMI

In 9 out of 10 cases when I boot 14.04.4 LTS no device for analogue sound output is detected. Then aplay -l gives:
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

However, in about 1 out of 10 cases though without any reproducible pattern an analogue output device is detected and I get from aplay -l:
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: CX20753/4 Analog [CX20753/4 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Even more strangely most of the time I get no sound whatsoever (neither speakers nor headphones) even when the analogue audio device is detected. To my great surprise, yesterday I booted and sound suddenly sound and speakers worked perfectly. Sadly, when I had to re-boot I got back to square one and now I have again no sound and most of the time aplay -l does not show the analogue output device.

I have to add that this was completely at random. I had not played with any config files or done anything. It worked suddenly, and now not.

This indicates to me that there is some config setting that has to be adjusted to force it in a mode where it recognizes and initializes the device correctly. But I don't know where to look nor whom to ask.

Any suggestions would be gratefully received.

I have already posted the output of the alsa info script here:
https://answers.launchpad.net/ubuntu/+source/alsa-driver/+question/286268

???