I did read your post, but it did not address everything that I suggested. I explained the main possibilities and how to narrow down the issue. Yes, I saw the SupportAssist message, but you should also do as I suggested to see what BIOS says:Hold F2 while booting, to enter BIOS. See if the charger is recognized. If you know both genuine Dell adapters are good, and they are both recognized on another Dell laptop, then probably you have a  bad charging jack or charging circuit. I would replace the jack.  
Hello, My Laptop is a Inspiron 3793 17 3000 Its showing the adapter is connected but it isn't charging. I've tried another genuine Dell adapter,and it shows the same problem. The power light on the side of the laptop comes on when you plug it in then goes off after  two seconds. I did a diagnostic check and it came back with this report (see photo) Thank you. [IMAGE][IMAGE]   
The AC Power adapter wattage