Laptop won’t turn on ( possibly burned )

I have plugged in external CD room to an USB port. Extra external power supply was connected to the external CD room. when I plugged in the cd rom to the laptops USB port I heard a noise, something probably burned. laptop won’t turn on. I have opened the laptop and I don’t see anything burned on the motherboard idk what it might be. charger works fine. any suggestions

thanks in advance for any help