I HAVE A WORKING SOLUTION !
After one morning when I woke up and there was no power going to my typecover, not working even in BIOS. I did all the things that were suggested in the forums. I put the typecover in the fridge, uninstall and install drivers, update and firmware and nothing worked (as it was stated in the forums, but I had to try).
I remember that when I lost all the functionality and power to my typecover the Surfave Pro 4 battery was drained to zero. In some forums people suggested that the problem might be caused by the battery.
Those are the following steps I made to fix my typecover problem :
1 - Unplugged the typecover and uninstall its drivers from "Device Manager"
2 - Install Battery Eater (http://batteryeater.com/) and run it until the battery dies.
3 - Leave the SP4 for 24 hours without any power.
4 - Put back the typecover and the charger to the drained SP4.
5 - Press the Power VOILÀ
This proves that patience and fasting solves any problem. Have a great reunion with you loved typecovers !