ASUS P9X79 PRO USB ports issue

Discussion in 'Asus' started by piowoc, Sep 7, 2014.

  1. piowoc


    Sep 7, 2014
    Likes Received:
    Hi guys,

    here is the strangest problem I have ever experienced with my PC:
    Board: ASUSTeK COMPUTER INC. P9X79 PRO Rev 1.xx
    BIOS: American Megatrends Inc. ver. 4801 dated 07/25/2014
    Running Windows 8.1 with all latest updates, even the optional ones.

    It has 2 ASMedia USB 3.0 controllers, one for the 2 ports on the front panel and one for 4 ports on the back.
    The driver I have installed for them is ASMedia ASM104x USB 3.0 host controller ver. dated 3/26/2014.

    I have 3 external USB 3.0 drives:
    - two of them are Seagate Expansion 4TB Desktop External Hard Drive USB 3.0 (STBV4000100),
    - one of them is Seagate Backup Plus 4TB Desktop External Hard Drive USB 3.0 (STCA4000100)

    Since last week my computer doesn't recognize the Backup Plus drive at all, but there is nothing wrong with the drive, because it works perfectly with my laptop, though strangely enough it's recognized by only two USB 3.0 ports of the laptop and not by the other to.

    As far as the Expansion drives are concerned the situation is even more weird, because one of them is recognized always, no matter to which USB port I plug it in (USB 3.0, or USB 2.0), even through the USB 3.0 hub.
    The other one, which is exactly the same model, but bought at a different time, so it probably has a different firmware, is recognized only if I connect it to one of the USB 3.0 ports on the front panel.

    Here is what I tried so far:
    1. It's not related to USB 3.0 cable, or power supply of the external drives.
    2. It's not related to the Power Options - all power saving options for all USB ports and controllers are turned off.
    3. It doesn't seem to be related to IntelĀ® USB 3.0 eXtensible Host Controller Driver, which I installed for USB 3.0 support and then turned back to ASMedia drivers, which are a bit newer.
    4. It's not related to Legacy USB support in BIOS, because I have it turned off now.

    So, I am running out of ideas.

    Can anybody help me?

    Your reply will be appreciated.
    piowoc, Sep 7, 2014
  2. piowoc


    Sep 7, 2014
    Likes Received:

    actually I was able to solve the mystery, at least partially.
    As I mentioned before I have 2 identical Seagate Backup Plus external drives, so this morning I swapped the bases of them. The base of this drive contains the plugs for USB 3.0 and power. This solved the problem, which I assume was related to some electrical issue of the USB 3.0 plug of the drive, which my Pc wasn't able to recognize. This may be due to some bent pins of the Micro-B USB 3.0 plug:{47}-3.0-Connectors-&-Pinouts.html

    So, the moral is not to connect and disconnect this type of plug frequently, because otherwise it may get worn out and stop working properly.
    Fortunately for me the base containing the plugs is detachable and Seagate agreed to ship me a replacement at no cost.

    OK, so another mystery, which remains to be solved is that one of my Seagate Expension 3TB external drives is recognized only if connected to the USB 3.0 port on the front panel of my computer. If I connect it to the USB 3.0 port on the back it causes disconnection of the other USB devices and still it's not recognized by the system (Win 8.1). If connected to the USB 2.0 ports it's not recognized at all, no matter if it's USB 2.0 port on the front, or the back of the computer.
    The other Expansion 3TB drive I have works just fine with all USb 3.0 and 2.0 ports, no matter which USB cable I use.

    My assumption is that it may be the same issue as with the Backup Plus drive, but why would it be then recognized by the front USB 3.0 ports, as well as by any USB ports on my laptop?
    I tried different USB cables for it and it doesn't make any difference, so I am a bit puzzled now.

    Any ideas will be greatly appreciated!

    piowoc, Sep 8, 2014
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