My computer specs are as follows. The computer is almost 1 year old. It is custom built:

  • Motherboard: ASUS h510m-a
  • OS: Windows 11
  • PSU: EVGA 500BR

In the past hour, I have connected multiple mice and one keyboard, and they have all been fried. After some time of using them, I received an error that the last USB device I have connected to this computer has malfunctioned, and they stopped working on all other devices. This applies to both wired and wireless keyboards and mice.

Several weeks ago, one of my RAM sticks randomly died, and I had to remove it otherwise my computer was stuck in a blue-screen loop. I think this might be connected somehow.

Why is this happening? What part is causing the issue and how can I fix it?

  • 1
    are these USB 3 ports?
    – Keltari
    Mar 22, 2023 at 23:53
  • 2
    You can't just fry stuff without adding salt my man xD. On a serious note, you may have messed around with some wiring that's causing that
    – chx101
    Mar 23, 2023 at 11:05
  • 35
    Remove your hard drive lest you lose your data.
    – DKNguyen
    Mar 23, 2023 at 13:44
  • 11
    Usually I would suggest to make sure your backup is up-to-date if your PC starts acting up, but, given your special situation, I suggest you do not connect the external hard drives you use for backups to this PC any more (because you have backups of your important data on external hard drives, right? RIGHT?)
    – Heinzi
    Mar 23, 2023 at 19:08
  • 8
    That immediately rings the PSU GONE BAD BELL here! Check your 12V and 5V power!!! (Sorry, I just noticed, that you've found the issue already in a comment below)
    – Caeleste
    Mar 24, 2023 at 8:34

5 Answers 5


Stop using your computer and turn it off. There is definitely a hardware fault in your computer.

If these are USBv2 ports, then it definitely sounds like 12 or more volts is being sent through the USB power lines. This is what is frying your devices. It could be a short somewhere in the motherboard, the internal USB hub, or in the USB controller itself.

If it's USBv3... Well, I haven't heard of a USBv3 controller sending more power to something that has not negotiated for more. However, it's still probably a short.

First thing to do is contact the manufacturer and talk to their support. If it's under warranty, get the motherboard replaced.

If it is not under warranty, you can take it to a reputable computer repair shop. Depending on the issue, they might be able to repair it, but this is not likely. They will probably recommend a new motherboard or the advice in the following paragraph.

Another possibility is if it's just the USB bus that's the issue, stop using it and get a PCI/PCIe USB add-on card and only use its ports.

  • 35
    Since a RAM module was also (probably) fried, I'd rather think it's an issue with power distribution on the board or maybe in the power supply than an USB-only issue.
    – arne
    Mar 23, 2023 at 9:59
  • 9
    if the RAM was fried, its not likely the computer would work at all. It could be a power supply issue, but if more voltage was coming out of it on the 5v rail than its supposed to, there would be other much more serious problems occurring.
    – Keltari
    Mar 23, 2023 at 14:13
  • 16
    * If it's under warranty, get the motherboard replaced.* A problem on the 5V line is likely to be a problem with the power supply. The motherboard is probably damaged too, but a new one will go the same way if connected to the dodgy PSU
    – Chris H
    Mar 23, 2023 at 14:45
  • 4
    @ChrisH it appears to be a dodgy PSU which is giving 13.3v and 5.6v on the 12v and 5v lines respectively. If I RMA the PSU, do I need to get the mobo replaced also? Mar 24, 2023 at 7:36
  • 1
    But note that testing a power supply with no load at all is a poor test. Hopefully you had something using power when you tested it, because the voltage specs only apply above a minimum current. This confused me recently when working on a very old machine - the -5V line was all over the place because the PCI card I'd removed for testing was the only load on that line
    – Chris H
    Mar 24, 2023 at 8:49

This sounds like a bad power supply.
Did you by chance buy a cheap non-quality brand and put it in a power-demanding machine? Could also be faulty unit.

  1. Stop using the machine. If it already fried a RAM stick and now USB devices, something is horribly wrong.
  2. Get a multimeter. Set to 20-volt range and shove the probes into free Molex/PCI-EX/CPU power jack. You want one yellow and one black wire slots. The reading should say 12V ±5%. 11.8V or 12.2V are fine, 10V or 14V are not. If anything is fishy, dump the PSU and get a replacement. You will have to power the PC for this measurement; shut it down afterwards.

Molex female connector

  1. Next you want to measure the 5V rail. This is easiest done at legacy Molex connector, if your PSU has one, otherwise a SATA-Molex adapter is handy to have just for this. Measure between red wire and any of blacks. Should be 5V. I strongly suspect this will not be 5V or becomes something horribly wrong when using the machine.
  2. If both 12V and 5V look fine, it could be a problem with motherboard itself. You need to measure the USB rail voltage. The measurement is done between two outer 'lips' in the USB socket, but this can easily cause short to chassis. If you have an old cheap USB 2.0 cable or anything throwaway with USB 2.0 plug, you can snip the cable, put the plug in, and measure voltages between each pair. You can try that on another USB device to find out which cables are the 5V rail. Measure your PC USB, it should be 5V per spec.
  3. If you're not good with multimeter, try borrowing a high-quality PSU of the correct power rating from someone and run PC off that.

There are two possible results for your findings:

  1. The voltages are dropping below spec, all of them. This means some components will brown-out and PC cannot see them. Replacing PSU will solve issue and components are actually fine.
  2. Some voltages are overshooting and some components got fried. Replacing PSU will not fix them.

Also, document your findings and damages; if PSU looks bad, get a replacement, and try charging the seller for broken parts.

  • 2
    Welcome Thomas, hope you have a useful experience on this site. Question: Could you perhaps post pictures with point 2? Of what should look like? For those of us not so well versed in electrical plumbing stuff? Or just link to pictures you find online. Thanks. Mar 23, 2023 at 9:26
  • 2
    @GwenKillerby I do not know how to embedd a picture, but found an instruction online (link below). If you do not have practice measuring things with multimeter, ask someone more experienced for advice, or try replacing power supply with known working unit. Multimeters are generally safe to poke into places when set to Volt mode, but it is expensive electronics we are talking about. instructables.com/…
    – Thomas
    Mar 23, 2023 at 11:45
  • 2
    @Thomas See superuser.com/help/formatting and superuser.com/editing-help#images for how to insert images. Mar 23, 2023 at 12:05
  • 9
    you can put the plug in, snip the cable, close but no: cut the cable first then plug it in, otherwise you'll short everything when you cut.
    – Chris H
    Mar 23, 2023 at 14:42
  • 3
    Measuring 5V at a Molex connector might not be useful in this case — USB ports are often powered from the 5VSB output of the PSU (so that you can turn the computer on from an USB keyboard), which is different from the 5V output that goes to regular power connectors. Mar 23, 2023 at 15:51

In the past hour, I have connected multiple mice and one keyboard, and they have all been fried.

This is not a driver issue.

Some hardware has failed inside - impossible to say what part but something is providing overvoltage to the USB ports.

You need to get the machine serviced and repaired before more damage is done.


You have connnected the USB2 header in the wrong orientation, resulting in power being sen on the wrong pin or the data lines.

  • I don't think this should be down voted. Given the information in the question, this is an entirely plausible answer. Yes, most modern cases don't let you rearrange the pins for front panel USB ports. That doesn't mean it's true of every cheap or recycled case. This answer seems like it would be useful for future readers who have the similar symptoms. The D+ line operates at a lower voltage to the VCC line. Devices can be fried by incorrectly wiring pins to a motherboard header. Mar 29, 2023 at 0:34
  • I can 100% confirm this is a possible thing. I don't remember if I had a whole ass 10-pin connector (with just 8 sockets wired though) or I had a case that was separating each USB port on individual headers (meaning again that there isn't just one single unmistakable orientation for both), but there's def designs more susceptible than others.
    – mirh
    Jul 26, 2023 at 23:46
  1. Update the USB driver

    • Click the search icon in the taskbar, type device manager, and click Applications in the results Picture1

    • Select the Universal Serial Bus Controllers section to expand it, right-click the first controller, and select Update Driver. picture2

    • Now select the first option to search for drivers automatically. picture3

    • If the system finds a new driver, it installs it. You can also click Search for an updated driver on Windows Update if you already have the latest driver. picture4

    • This will take you to the Windows Update menu. Click Advanced Options. picture5

    • Now select Optional Updates. If you find any driver related updates, select and install them picture6

  • 31
    this is not a driver issue
    – Keltari
    Mar 23, 2023 at 0:38
  • 10
    While I cleaned this answer up, @Keltari is correct: There is no way a driver issue would cause physical damage like this. Your answer is detailed and well intentioned, but it’s not a driver or software issue. The system is shorted or damaged somewhere. Too much power to USB ports? Who knows. Mar 23, 2023 at 0:54
  • 14
    Listen. You cannot fix every usb related problem by saying to fix the drivers. It's clearly a hardware issue. Mar 23, 2023 at 1:03
  • 22
    Support: "Did you install the latest Windows patches? If not, we cannot help you." Mar 23, 2023 at 13:50
  • 7
    Hi Ci Ho Yin - I see that you are a new contributor. It may be that English is not your most fluent language. When we say that something is "fried", we are talking about hardware that no longer works on any system - not just the one in question. It usually means that the hardware is electrically damaged beyond hope of repair. Mar 23, 2023 at 19:35

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