B.Mini Ex 2 stopped working

Shop Forums QnA B.Mini Ex 2 stopped working

This topic contains 12 replies, has 2 voices, and was last updated by  flashteker@gmail.com 6 years, 5 months ago.

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  • #5904



    I purchased a B.Mini Ex from you with SMD pre-soldered.  It was working fine for about three weeks, when all of a sudden it stopped working.  It was properly connected by USB, but the LEDs turned off and no key presses did anything.  I tried re-connecting it, and tried several different USB cables and different computers, but I can’t get it to work at all.  When I plug it in, I get the message from WIndows: “USB Device Not Recognized.” When I go into the devices confirguartion screen in WOndiws, I see “Unknown USB Device (Device Descriptor Request Failed) – Driver Error.” Please help! Thank you,




    Also, I should mention:

    I have disassembled the board, and am still getting the message even when I plug the PCB in without any switches (I had used holtites so it was easy to remove everything).


    Hi Sorry for your inconvenience.

    Could you try to remove a driver and replug your keyboard?

    -> Remove device drive(HID drive) from OS device manager and replug the keyboard
    If you install it properly, it looks like this

    If you want to clearly remove drive, please see this page:http://winkeyless.kr/how_to_remove_driver/




    I did what you suggested.  When I plugged it in again, the same error message came up.  I took a screenshot of what the program said about the device.  It’s the one with the blue line.  I had to take two screenshots to get all of the information.

    You must be logged in to view attached files.

    Could you try to upload the latest firmware by using the latest BootmapperClient in bootloader mode?

    1. Downloading firmware and BootmapperClient

    Firmware Installing and Setting

    2. Uploading firmware in bootloader mode
    1) Connect Keyboard as bootloader mode (While pressing LCtrl, connect it to PC)
    2) Start BootmapperClient and press “Options” tab.
    3) Press “Firm up” button at Utils area.
    4) please select a proper hex file.
    (Firmware is “ps2avrGB_NKRO.hex”, not the ones starting with “keymap_xxx”.)




    OK! I followed your instructions. At first, it was still not working. But then I messed around a bit in Bootmapperclient. I clicked “EEPROM All Clear,” and then it worked! Everything seems to be okay now. Thanks for the help 🙂



    It ttttttttttttturns out that iiiiiiiiiiiiit is not wooooooooooooooorrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrking well

    I wrote the previous sentence with the B.mini… It is acting very strangely.  Lots of keys get “stuck,” as you can see. Once, I even got a pop-up from Windows saying that “A USB device is setting up,” as soon as the characters started repeating.

    I know it’s not a problem with the switches; these are the same ones that have been in the keyboard and were previously working just fine. Any ideas?
    Thank you.







    Oh no… I am back to the beginning:  the keyboard doesn’t work at all, and I get the “device not recognized message.”  Now when I try to upload the new firmware, it doesn’t even work.



    I guess you chose “ps2” connection mode.

    In BootmapperClient, could you change it to “Set USB” and replug your keyboard?




    I have done that. I keep having the same problems from the beginning. :((

    Do you have any other ideas?



    I think there is no other way but sending it back to me to fix it.

    Could you tell me your order number?

    Then I’ll tell you where you send it.


    If it is due to your fault, I hope you to understand that I’ll charge you for the delivery fee.

    And from now on, shall we talk through emaiL
    (My email address is flashteker@gmail.com.)





    Hi, I’m in the United States. Am I correct that you will pay for me to send it back to you?


    Edit: Also, I haven’t mentioned yet: I was using the Holtites you suggested with this keyboard. Is there any way they could have been causing an issue?

    • This reply was modified 6 years, 5 months ago by  ezraG.


    1. The delivery path will be like this
    – A.Your home -> B.delivery office in USA(I will tell you where it is) ->C.S.Korea (to me)-> D.your home
    – You have to pay the delivery fee from A to B(domestic price)
    – I’ll pay for B to C
    – If the Keyboard has a defect, I’ll pay for the route from C To D. If not, you have to.(around $26)

    2. I don’t think the holtites made such a problem.

    3. Please let me know your order number, and talk through email.

    4. If you want to send it to me, I will let you know the delivery office in USA, which I made a contract with.



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