USB problems

By vale46 ยท 10 replies
Apr 14, 2008
  1. Hi all,
    Need some advice please on my friends pc. Last night he heard a big bang from his fuse box and upon investigating it discovered a fuse had blown...not that strange i hear you say ! but....later he went to turn his pc on and it didnt work. so because he know nothing about them he ask me to look at it for him ( i dont know lots myself, just basic stuff). First thing i checked was the fuse and it was fine, i have a spare PSU so i popped it in and works so i guess his just blew although how it blew without been switched on is a mystery (powersurge ???). Anyway i only had a usb keyboard available at the time to plug in to test if the pc itself worked fine and it seemed ok so i took it back to his house and connected it all back up for him only to discover that there is a serious issue now with the USB ports.
    When i plugged his ps2 mouse and keyboard back in, all was fine so i plugged his usb printer in and again all fine, i then plugged his usb speedtouch modem in and that worked but now the mouse stopped working !!! so i tried the usb port the printer was plugged into although the modem worked again the mouse didnt. This is the same for usb memory sticks, they work but stop the mouse from responding. The only thing that lets the mouse function is the printer, and that dosent care which usb its plugged itnto.

    So to simplify. psu blew up so i replaced it and tested pc with a usb keboard. Took pc back and plugged in ps2 mouse and keyboard and all works fine, Plug usb printer in and all is fine, plug any other usb device in and the mouse stops functioning even though the usb devise works fine !!! ????

    Sorry for the long winded explanation, hope it makes some sence and thank you in advance for any advice.

    Best regards,

  2. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Hi Vale,

    The PowerSupply probably had an electrical charge sent up the Earth connection in the PowerSupply which blew it (so therefore it doesn't need to be on)
    Also, as a good measure physically unplug the power plug in electrical storms - I always do)

    The Motherboard's most sensitive part is the USB (with many recorded faults from electrical surge)
    Which means the Motherboard is also possible shot as well :(

    There is one option, and that is to discharge all power and reset the bios chip.
    This is a small battery on the Motherboard. But you will need to refer to the motherboards manual on how to reset the bios (hardware experience and AntiStatic precautions need to be adhered to)
  3. vale46

    vale46 TS Rookie Topic Starter Posts: 160

    wow, this sounds it ? or is it straight forward if i have the info needed.
    Would i assume that just reformatting isnt going to help here then ? i know a limited amount of pc bits and bobs but i havent tried anything like this. I once downloaded a cpuz ? file for the pc in question. i think i might still have it......yes i have ;) is there any info here that might help me ?
    This was my old pc hence the cpuz and i never had a problem with it, i only upgraded due to a program i use and sold my old one to my mate and guess it goes wrong hahaha.
    Thanks kinsland.
  4. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Yes this helps me to know what you have

    Your System:
    Here is a pic of your internal M/b (I had to quickly go over to you and take a picture!)
    The shiny round circle (left hand bottom corner of the gold square)
    Is your CMOS battery
    (The white round circles, are your M/B mounting screws)

    Info here on how to actually open the case (can be difficult if you don't know)

    More info on dismantle here:

    If you are not comfortable in removing the CMOS battery or retting the CMOS from the motherboard level, you may need to seek further advice (from someone able to look at you computer onsite)
  5. vale46

    vale46 TS Rookie Topic Starter Posts: 160

    kimsland your a life saver, and next time you pop over to take a pic let me know and i will put the kettle on ;) opening the pc isnt a prob, i have put my own ram, psu and graphicis card in it so far,

    So, do i just de-stat and remove the battery and then replace after a min or so. and if so is that it or do i need to do something in the bios ? that is something i would need a little guidence with if so.

    Thanks ever so much for your help and interest so far kimsland.

  6. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    You know I read the manuals and everything, but I can't see where it says reset bios.

    Sometimes there is a jumper next to the CMOS battery that needs to be detached, or moved to the next set of pins (but I can't see it, in the small pic above.

    Therefore remove the battery (also power cord out)
    Hold in the front power ON switch for 30 secs
    Re-insert the CMOS battery

    Test again

    Note: it's more likely that you have unrecoverable fault to the M/b hardware
  7. LookinAround

    LookinAround Ex Tech Spotter Posts: 6,491   +184

    If i may throw in some info (which you can decide is relevant or not)

    What version of Windows is running? There is a little known problem that can occur with XP SP2 and USB (I've been running XP SP2 since it was released without ever having this problem or even ever having heard of it until recently when helping a friend with his computer. After all other approaches failed i disconnected all devices and removed power "just based on computer intuition and for the "helluvit" while we hung out. Gave it one more try before i left for home and everything worked again! I subsequently searched and found a documented issue about XP SP2 and USB)

    Power down the computer, disconnect your external devices, and unplug all power cords. Leave it sit unplugged for at an hour or more. Then try again.

    (it wouldn't drain CMOS battery but some of the symptoms sound eerily similar it might be worth just trying unplugged power cables if you're running XP SP2)
  8. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Yes USB and what it is stated in CMOS can affect install of Windows

    One way to overcome this, is to remove all USB devices and use PS/2 Keyboard /Mouse
    Then also disable USB in CMOS fully
    Even go as far as disconnecting front USB from the motherboard

    Xp will usually Repair or Reinstall at this point

    Once Windows is fully operational again, you can re-enable USB again

    Sometimes this works, sometimes no
  9. LookinAround

    LookinAround Ex Tech Spotter Posts: 6,491   +184

    yes.. but fyi.. there is a specific problem in specifically XP SP2 which can violate USB 2.0 and hose things up which appears to be remedied by the unplug/unpower all the external cables/cords. If in fact this is related to this problem (and i don't know if it is or is not) was just suggesting trying as described (couldn't hurt) if thread owner was having problem figuring out the CMOS part of a solution.
  10. kimsland

    kimsland Ex-TechSpotter Posts: 14,523

    Yes stated above

    Also if USB does not work anylonger on your M/board, you can purchase USB 2 PCI internal cards (this will enable USB to remain disabled in CMOS - if it is faulty)
    Basically a work-around lookinaround that's what I've found in a mound of these rounds (by the way is sound working :) )
  11. LookinAround

    LookinAround Ex Tech Spotter Posts: 6,491   +184

    trying all these fixes are wearing me out.

    And, no. No sound.. Just trying to find all these fixes are runnin' me into the ground ;)
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