Dell laptop acting strange, and smoked came out of air vents

I have a Dell Inspiron 15 7559, the one without the touchscreen. Recently I was having issues with trying to get it to turn on it was just acting strange all along. I recently kinda got it to work, but when I was using it smoke started coming out by the vents, I quickly pulled out the power cord and pull the battery out. At first I thought my CPU or GPU had fried, however, I can't seem to find what caused the smoke, but I can smell, what smells like burnt wires. I have knowledge on how to fix a computer, I helped fix both Windows and Chromebook OS laptops at a school. I never had a single issue nor have I ever had a computer catch fire. I have quite not powered on the computer as it would be considered a fire hazard, however, it's out of warranty, I have no clue to what to do now.