Re: dell inspiron 15 5520 battery not charging
Unplug the adapter from the system. Is the LED on? If not, the adapter is bad; replace it with a new OEM Dell adapter.
If the LED is ON, does it stay on when you plug in the system end? If yes, press F2 at powerup and see if the adapter is recognized. If it is, but the battery won't charge, the battery is bad.
If NO, the LED goes out -- or if the LED stays on but the system doesn't recognize the adapter (shows unknown at setup screen -- F2 at powerup), replace the adapter with a new OEM Dell unit.
If that doesn't solve the problem, replace the DC power jack:
And if that doesn't fix the issue, the mainboard is bad. Replace the system board.