Well, I have a Dell Inspiron 5558 and it has been a great laptop for me, after few years I got a crack in the lcd back cover and the hinges were not in good condition so I decided to change it myself, I watched some videos about replacing the back cover and I did the same , but after assembling everything I tried to boot it up and the display showed the BIOS saying "There is an startup issue in your computer" something like that and it was testing all the hardware , after 5 seconds the fan stops spinning and I get some burned plastic smell, well I didn't even touch the heatsink or the cooling fan ,so kindly help me as soon as possible.