My computer reports a USB current-overload error even when nothing is plugged into any USB port. Several years ago, someone forced a plug into one of the rear USB ports, bending its internal contacts. I carefully pulled the contacts forward with pliers, and the port worked without causing problems for a long time. The error has suddenly returned, even though the contacts still appear straight and nothing has recently been connected.
I have an MSI MPG Z390M motherboard and opened the case to see whether I could disconnect the faulty port. I understand that front- or top-panel USB ports usually connect through removable cables, but this is one of the motherboard's rear I/O ports. Is there a safe way to disconnect or disable only that damaged port, or does the motherboard need to be repaired or replaced?
2 Answers
A USB overcurrent warning with nothing connected usually means the damaged port itself is shorting the 5-volt supply. You can leave that port unused, but if the warning prevents the computer from starting, the practical fixes are board-level repair or replacing the motherboard. Disabling USB in the BIOS may turn off the controller, but most boards do not provide a way to disable one individual rear port, and repeatedly powering on with a short can stress the USB protection circuitry.
Because it is a rear motherboard port, it is soldered directly to the board rather than connected through a removable cable. The motherboard is not automatically bricked, but you generally cannot unplug just that port internally. With the computer fully powered off and unplugged, inspect the port closely for bent contacts, metal debris, or a contact touching the shell. Avoid continuing to pry on it with pliers, since that can make the short worse or damage the board.
That makes sense. I was hoping there would be a header I could disconnect, but since it is on the rear I/O, I will stop trying to pull the contacts around.
If you are comfortable with electronics repair, a technician may be able to replace or remove the damaged connector. Do not cut random traces or wires inside the case, since the rear ports are part of the motherboard circuitry and that could cause permanent damage.