You can recover the files by removing the solid state drive and mounting it into an external USB adapter card -- example: [URL]   If the system is in warranty, then call Dell for repair. If the system is out of warranty, you're going to be faced with replacing the system board.  This will be a minimum of $200-300 depending on the CPU, plus labor.  That may wind up more than half the initial purchase cost, at which point you may be better off replacing the system rather than repairing this one.  
I own a dell Inspiron 3511. I was using it a couple of months ago. And the battery was low. So I plugged it in and the laptop just froze and the laptop turned off. I checked it out and the charger was fine. Also there weren't any physical damage to the hardware. I don't now a way of fixing it and I did a hard reset  to the laptop but it didn't seem to work.
Dell inspiron 15 3511 no power/not charging.