Hi [NAME] thank you for update.  Does your ac adapter (and its microprocessor) power another Dell laptop. If yes, the ac adapter's microprocessor does not have a fault, and eliminates your ac adapter from being a problem.  Having disconnected battery, its communication with laptop's charging circuit is also removed. This eliminates your battery from being a problem.  The laptop has an undetermined fault and requires specialist diagnostics. Please consider the $100 Dell Laptop Repair | Dell Repair | Laptop Repair | Notebook Service Center (parts-people.com). They will investigate and tell you what is required to fix this problem. 
I am having issues with a m17 R4. This laptop does not detect power for the power jack for some reason, it will power on and charge via usb c but nothing else. I have replaced the charge port on the laptop with 2 spares(yes I tried power cycling). I now have it at a shop and they are having problems figuring out the issue as well. The mosfets are ok and there are no hot spots on the board. Led on the power adapter does not go out and universal power adapters show no life either. I am thinking that whatever IC controls power and charge has a loose pin but I wont pretend to know how dell handles there power as I do not typically handle repair of consumer computers. If anyone knows any information on this laptops power circuitry please help I don't know where else to go. 
m17 R4 power issues