Hi, Sorry for the late responce. After doing some research I found that sometimes the laptop wakes up in Tablet mode and keyboard and mousepad are in active! The solution is to manually fully open and close the laptop lead to enter and exit the tanblet mode to fix this issue. Thanks.
The keyboard and touchpad of the laptop stoped working! Even when the laptop is booting not key is working (for example if I press Capslock, no capslock light is switched ON). the only working key on the laptop is the power key. I only can use the laptop with external keyboard and mouse.  I run the Diagnostic Test from the BIOS while disconnecting external keyboard, but it cannot find any failure. Has anyone experienced the same problem? Please advise if you have any solutions. Thanks.
Dell XPS 13 7390 2-in-1keyboard and touchpad not working