I actually had this happen, first one, USB Fried and the cable, but the USB port was still working, Second one, Fried again and this time fried the USB port, thankfuly my computer still is running as I don't have a backup like this, and I'm really annoyed that the replacement botherboard I got -actually- killed the USB port this time, let alone the fact of replacing the motherboard, since the mainboard was -hotglued- for the wires, potentially ruined the wires for t he Z-bed leveling detection.

This is kind of happening to me, Replaced the mainboard and its USB shorted SO i tried to switch back to the initial one which could at least print from SD Card, in my case the light flickers right when I turn the printer on, and you can hear the 'elecric noise' of when the sensor should trigger, but it doesn't respond to it and just digs into the bed.

I backed this from my first printer being an Ender 3 Pro and thought "Dude, Creality printers are nice, This will make a good second printer." ...I'm steadily regretting my decision, as two USB fried mainboards one fried USB cable from the first, second saved from paying hyper close attention when plugging it in and one Fried USB port on my computer....

I actually had this happen, first one, USB Fried and the cable, but the USB port was still working, Second one, Fried again and this time fried the USB port, thankfuly my computer still is running as I don't have a backup like this, and I'm really annoyed that the replacement botherboard I got -actually- killed the USB port this time, let alone the fact of replacing the motherboard, since the mainboard was -hotglued- for the wires, potentially ruined the wires for t he Z-bed leveling detection.