Conexant audio device not found !!!!!!!!!

Inspiron 7568 2-in-1. 

i recently lost the audio on my computer, the audio shortcut on the taskbar is crossed and if I click it, it will automatically launch the troubleshooting, which detects the problem and asks me to restart. when i do, there is no change and the process is repeated. 

I entered device manager and sound, video and game controllers did not appear, when i showed the hidden ones, they appeared, all of them had the message " not connected" and (Code 45). 

I then uninstalled all of the drivers of sound in there and restarted, the drivers were not re-installed. then i entered the dell website and downloaded the audio driver they have in there, installed and nothing happened. 

the problem is still the same and now i can not even find the drivers