Dell latitude E5440 doesn't charge or work even with AC adapter

Hi All

My Dell E5440 stopped charging with battery and I started to troubleshoot. I tried all the options to update windows and also to reboot the drivers but no success. During the process the battery power went down completely and now my laptop is completely OFF.

I'm unable to start it since it won't accept even AC power when I connected it. Can anyone suggest what should I do next?

I've already tried to remove battery and flush out static charge and other basic steps provided on Dell support posts. Please help here as a matter of urgency.

The laptop is new and less than a year so it's not a old battery.