I accidentally plugged in a mobile phone which shorted out. The USB port is still working fine, but could such events make my USB port or the motherboard fail?

  • My current laptop has short-circuit-protected USB ports, but not every computer is well-behaved under these conditions. My old laptop once shut down abruptly when the power lines were shorted on a USB port.
    – bwDraco
    Commented Feb 14, 2016 at 22:52
  • Knowing your laptop's model might help a little. Once you create an account here, you can edit your question.
    – Ben N
    Commented Feb 14, 2016 at 23:10
  • "could the event make my USB port or the motherboard fail soon" this will draw opinions rather than answers, no way anyone can know what will happen in the future.
    – Moab
    Commented Feb 15, 2016 at 22:56

3 Answers 3


Generally a host USB port will have ESD protection on the data lines, and power will be supplied through a current limiting power-switch like the TI TPS2557. These devices will limit current to a programmed amount (generally 500mA for standard USB ports), and have output signals in event of a power fault that go back to the USB controller informing it of an over-current event.

Did your event degrade long-term reliability of the part in question? Unknown without further information about the event and ICs involved. I think you are probably fine though -- any reasonable laptop design would have that current limiting device there, and those devices themselves generally have thermal protection to keep them inside their SOA.


Many motherboards uses PTC thermal cutout as the short circuit protection for the USB ports. This device go into high impedance state when its temperature goes above certain limit during short circuit. If this is what being used on yr laptop motherboard then you got nothing to worry.


You'll probably find a lot of requirements for short-circuit protection in the USB specifications (which probably vary depending on the USB port type you have on your laptop). And your USB port manufacturer probably followed the specs when implementing the hardware and software aspects of this protection. But there's no way to tell what the long-term effect of a short circuit might be.

You must log in to answer this question.