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Motherboard Destroys USB Devices

Discussion in 'Hardware' started by kyran64, Jan 29, 2013.

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  1. kyran64

    kyran64 Thread Starter

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    So, here's a fun problem I've never seen before. I just put together a desktop using an Asus M5A78L-M LX Plus motherboard. The case I'm using has USB ports on the front that don't seem to work regardless of which set of pins I plug them into on the motherboard.

    I'd pass it off as a problem with the case except that even the USB ports on the back seem to be...odd.

    The first mouse I tried using is a tiny logitech optical mouse I picked up years ago for 5 bucks (nabbed a few of them actually). The optical light would come on but the computer wouldn't register it as a device that had been plugged in. Oh well. I plug it back into my old computer. ...mouse doesn't work there now either. It's an old mouse...maybe it just coincidentally went bad right then. So I pull out an extra mouse...fancy gaming mouse that I never use because it's too bulky for my taste. It works just fine.

    I grab a thumb drive to move some files from one computer to the other. The light on the thumb drive which is ALWAYS on when it's plugged in...won't turn on. An external USB harddrive works just fine though.

    In my shuffling to do things, I grab another one of the little cheapy logitech mice so I'm not moving the bulky mouse back and forth from computer to computer. The logitech mouse which WAS working on the computer it had been plugged into ALSO quits working. Ok, this can't be a coincidence. On a whim I check the thumb drive in my other computer. It doesn't work anymore either.


    My thought is that it's obviously a problem with the new motherboard...probably the USB controller working at too high a voltage for some reason and burning out smaller devices. Has anyone seen anything like this before though? Could it be a problem with the power supply instead?
     
  2. kyran64

    kyran64 Thread Starter

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    The power supply is a SeaSonic S12II 430B 430W ATX12V V2.3/EPS12V 80 PLUS BRONZE
     
  3. Triple6

    Triple6 Moderator

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    Have you tried pulling the motherboard out of the case and not connecting the front USB ports at all and seeing if the back USB ports start working properly? Could be a short while it's in the case.

    A 430 Watt PSU is kinda low but it depends what else is in the computer, if you're only using integrated graphics and don't have a lot of drives or cards then its suitable. It's a good brand as well but it could be faulty, but if the PC is running fine otherwise I'd suspect a short or motherboard fault first. If you have another PSU you can definitely swap it out.
     
  4. kyran64

    kyran64 Thread Starter

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    Thanks for the response Triple6!

    I haven't done much of anything to troubleshoot this one yet..after finding out that 2 of my favorite mice and the only USB stick I had immediately on hand were dead I just put the darn thing in my back room until I felt like dealing with it again.

    I've searched around a bit to see what other people have done about this problem. Most of the issues seem to be with case-mounted ports being improperly wired at the factory..so I'll take a look at that..maybe use a battery to charge the lines and check the voltages across the terminals..or something. (would it be safe to probe the pins on the motherboard with a multi-meter while it's on and running?)

    I've also looked up a guide on how to check the voltages in a PSU so I'll be doing that as well.

    I've only found one other occurrence where the rear ports were destroying things (like mine)...and the only solution anyone could offer up was that the I/O plate might be shorting out against the USB devices.

    So taking the motherboard out sounds like an excellent idea..but...I'm fresh out of devices I'm willing to sacrifice just to tinker.

    Does anyone know of a slightly less lethal way to test and see if a USB port is shorting out?
     
  5. managed

    managed Trusted Advisor Spam Fighter

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    Rather than pushing meter leads into USB ports you could make use of one of those dead mice by cutting the wire near the mouse end and baring each lead. Then trace which wire goes to which contact at the USB plug end. Then plug into each USB port and check the voltages at the bare wires end. The connections looking into the USB plug should be like this :-

    [​IMG]

    Checking for 5 Volts and Ground in the right places should suffice.
     
  6. dai

    dai

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    set it up out of the case on a piece of cardboard with
    cpu
    video
    ram
    speaker
    and see if you get post
    check you have the correct amount of standoffs no more no less
    that they line up with the holes in the m/board
    usually 9
     
  7. kyran64

    kyran64 Thread Starter

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    Ok. So I set my multimeter to 200m DCV. Checking against the casing of a usb plug and the motherboard plate on my currently working desktop, it reads exactly 0. Checking against the casing of a usb plug and the motherboard on the problem computer, it reads 0.4. So There's possibly reason to suspect something isn't grounded appropriately? Or does that even mean anything?

    Taking the motherboard out of the case there are exactly as many standoffs as there are holes in the motherboard to screw it down...six of them in the correlating locations.

    I looked up chart of all the pins on the main power connector of the PSU as well as a set of instructions on how to check it and a chart of the tolerances for each line. I only checked the 24 pin ATX connector but everything was almost spot on. I did not check anything under load but I'm comfortable in saying that the PSU is probably not the problem.

    To test the plugs in the front of the case to make sure they were wired correctly, I did as managed suggested and cut the cord off one of the mice the motherboard had already ruined. I checked the wires against the terminals in the plug and verified that they do indeed go to the terminals they are supposed to. Plugged it in to each USB port on the front of the front of the case then checked for continuity.
    - I find absolutely NO continuity off the +5V wire for either of the front USB port when checked against the wiring harness that plugs into motherboard. I DO find continuity when I test the usb +5V terminal against some of the wires on the front mounted HD Audio wiring harness.
    - The ground wires from both front mounted USB ports have continuity to the same +5V pin in the wiring harness.
    - The D+/- lines from the front mounted USB ports ALSO show zero continuity to the USB wiring harness...but they DO show continuity to the HD Audio wiring.

    I conclude then that the case was wired wrong.

    Now to test the motherboard out of the case:
    I didn't think to check the voltages for the terminals while it was still in the case..so I don't know what to compare it to testing it OUT of the case.

    To be clear: Some devices worked fine in the case.

    - I have a USB keyboard and a fairly high-end USB mouse that both seem to work with no ill effects. My external Western Digital HD works fine. Two cheaper logitech mice and a USB memory stick were all fried before I figured out it was destroying SOME devices.

    - Using the working keyboard and mouse, I was able to install Windows 7 on it with no problem...all of the software and drivers that came with the motherboard also installed without a hitch and...I hadn't plugged in speakers so I can't vouch for sound but ALL of the other onboard devices seemed to be working properly in Windows.

    So...I know the the wiring on the case is wrong and I can check the pins for the extra USB ports on the motherboard to verify whether or not they have power... but the ports in the back were the ones destroying the occasional device. Can anyone think of a way for me to check them without potentially sacrificing yet ANOTHER usb device? ..cuz I'm kind of running of out spares that I feel like paying for to replace.

    ...OR...should I just save myself the hassle and try to RMA both of them back to Newegg since the case is obviously wired wrong and the motherboard is destroying things?
     
  8. Amd_Man

    Amd_Man

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    Try unplugging the case usb connector from the motherboard. If those aren't hooked up right it can affect all the usb ports by overvolting them. Usually the motherboard will come up with a overvolting message on boot up and not start so it doesn't cause damage, but maybe that's not working. Just something to try!!!
     
  9. kyran64

    kyran64 Thread Starter

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    Thanks AMD_Man.. that will definitely be something worth checking out when I get another moment to look at it.

    Voltage coming out the back with the front ports plugged in...then without. If there's a difference I can feel better about plugging in another device to see if it fries :D
     
  10. Amd_Man

    Amd_Man

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    They are all run from a USB controller and over-voltage will fry devices when plugged in. The motherboard should warn you if that's the case, but who knows. I've seen so many weird things with computers over my years in the field.
     
  11. managed

    managed Trusted Advisor Spam Fighter

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    You can use the Usb lead you cut to check the Usb ports. Just plug it in, set the meter for the Voltage range that's higher but closest to 5 Volts, put the black probe on the wire that comes from the 0 Volt connector on the plug and the red probe on the one from the 5 V and check there is +5V.

    You don't need to test continuity to do the above..

    Don't let any of the bared wires in the lead touch each other when it's plugged in !
     
  12. kyran64

    kyran64 Thread Starter

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    Hmm. I did as Dai said and set the motherboard on a piece of cardboard with the CPU (and fan of course), RAM, Speaker...and the video is onboard. Plugged in the ATX connector and the line to the power switch on the case. I carefully made sure the motherboard was only on the cardboard with nothing else touching it. Turned it on and checked the voltages.

    Without the front-mounted ports plugged in, the voltage is 4.97.
    WITH the front-mounted ports plugged in (and HD Audio since that's how it was set up while it was destroying things), the voltage is....4.97.

    I hooked up the hard drive, DVD, and monitor and booted to Windows. Voltage wandered between 4.67 and 4.98 during boot then leveled out at 4.97 again after windows had loaded.

    *sigh* Still nervous, I plugged in my poor little Logitech v100 mouse (the kind that has already been demolished twice) to test it. ...and it works.

    So I'm suspecting the theory that the USB devices were grounding out against the case somehow is correct. The case already needs to be replaced because of the wiring issue...does this imply a defect with the motherboard as well? Everything 'appears' to be working normally out of the case....
     
  13. dai

    dai

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    4.67 is out of spec

    see if you can borrow a quality 550w psu to try it
     
  14. Simba7

    Simba7

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  15. kyran64

    kyran64 Thread Starter

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    It dipped only for an extremely brief moment as Windows loaded..just one sweep on the multi-meter. Any other time it has stayed right at 4.97.

    Any chance it might've actually just been a flicker as Windows loaded the drivers for the USB controller?
     
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