@tswanshi USB ports have resistors that act as fuses so a USB port should in essence not blow a motherboard. It sounds like the graphics part of the motherboard probably decided to coincidentally give up the ghost. Being a DELL, this is not wholly surprising as the majority of DELL laptops I have repaired usually are overheating due to the bad design of the heatsink and fan and the lack or too much of the thermal compound they use on the CPU and graphics chip.