First of all, this may sound like a duplicate post. But, my Mindstorms NXT 2.0 has been having the "Clicking Brick Syndrome".

I have been told that uninstalling the bossa driver then unplugging and replugging the brick offline will cause it to install correctly.

Unfortunately this does not happen and the bossa drivers reinstall. Anyone have any ideas that may help? I am running Windows 10.

  • I'm not familiar with the "bossa" driver. Do you mean the "Fantom" driver available at lego.com/en-us/mindstorms/downloads? Nov 12, 2015 at 0:09
  • for some reason it is installing a bossa driver instead of the the lego drivers
    – zcmckenna
    Nov 16, 2015 at 22:36
  • This was a really great help. On my computer there's no Arduino software, but the problem with this Bossa driver existed anyhow. Thanks!
    – user7269
    May 26, 2016 at 22:39

4 Answers 4


If you are getting tic...tic...tic then your brick is waiting for a firmware to be written to it. I would recommend looking at this for full instructions.

Basically, you need to re-flash the firmware onto the brick. I've done this a number of times as I use an alternate firmware called LeJOS (runs Java). There shouldn't be anything that breaks from this (not any further than what you've got). Make sure your batteries are not going to die on you while you re-flash the firmware. Just give them a charge.

  1. Do a hard reset on the brick (should be a paperclip in one of the bottom corners held down for a few seconds). This shouldn't be required, as your NXT is already in this state, but just in case.

  2. Connect your brick to a computer, it must have the Mindstorms NXT software installed on the computer.

  3. Open up Mindstorms NXT, and go to Tools->Update NXT Firmware

  4. Click "Check" and then "Download". This will install the firmware on the NXT.

You should now have a working brick. However, any programs you may have flashed to it are gone (and probably were already gone, as discussed in #1). All you need to do to restore those is write the programs from the Mindstorms NXT software on your computer.

  • 1
    the problem is the computer wont recognize the brick after i did that
    – zcmckenna
    Nov 16, 2015 at 22:38
  • @zcmckenna That is exactly what happened to my EV3 after upgrading to 1.10E. My antivirus started going crazy and called it "ransomware" and I kept getting a bunch of "error code 4" messages. But after a few hours it unexpectedly stopped. May 21, 2020 at 11:00

Read the RobotC NXT Forum thread Firmware Update & Arduino IDE Issues (Renamed). The only post that count is the 31th post. Simply go to the Device Manager with the brick connected, choose the Bossa Device, choose property, pilot update and replace the Bossa device by the Lego Mindstorm device.

Here are the explicit instructions from that post:

  1. Complete a Hard Reset on the NXT Brick
    • Push and Hold Silver Button on Back of Brick for at least 10 Seconds
    • You Should Hear a Clicking Sound
  2. Plug the NXT Brick into the Computer via USB Cable
  3. Click on the Windows Start Button
  4. Right Click on Computer
  5. Choose Manage
  6. Expand the Ports
  7. Right Click on the “BOSSA” Port
  8. Choose Update Driver Software
  9. Choose Manual Selection
  10. Click “Choose from List Provided”
  11. Select the Lego Option
  12. Open RobotC
  13. Click Robot and Download Firmware
  • thanks for the very helpful hints! I encountered same issue with installing LEGO Mindstorms NXT v2.0.f6 and Arduino IDE 1.8.2 under Windows 10. After uninstalling Arduino IDE and LEGO Mindstorms I reinstalled LEGO Mindstorms, but the "Bossa" Driver still persist after rebooting. After dealing with suggestions regarding the oemxx.inf files the only solution which worked spontaneous was the one from "jmarcr": "...replace the Bossa device by the Lego Mindstorm device" THX for this!!! :-) (Now I am curious looking to install Arduino IDE again...and see what will happen...) May 16, 2017 at 21:10

I found a similar issue here. It looks like the bossa driver comes from Aurduino.

That post recommends the following:

Option A:

  1. Make sure the NXT brick is disconnected.
  2. Open Control Panel/Program and Features.
  3. Find the "Arduino" entry. Double click it to uninstall the Arduino IDE.
  4. After uninstall is done, plug in the NXT brick. The correct NXT firmware update driver would be installed.
  5. Open RobotC and do the firmware update.
  6. After the firmware update is done, if you still want Arduino IDE to work, reinstall the Arudino IDE.

Option B:

  1. Make sure the NXT brick is still connected to the computer.
  2. Open an elevated CMD.
  3. Type "cd c:\Windows\inf"
  4. Type "findstr Bossa *.inf"
  5. Note the INF file name in the form of oemxx.inf
  6. Type "rename oemxx.inf oemxx.inf.bak" (Note: please substitute xx with the actual number reported by findstr)
  7. Open Control Panel/Device Manager.
  8. Find the Bossa Program Port device.
  9. Right click the device and select "Uninstall".
  10. Disconnect the NXT brick from the computer, wait a few seconds.
  11. Reconnect the NXT brick to the computer and wait a minute or two for the system to find and install the correct NXT firmware update driver for it.
  12. Open RobotC and proceed with the firmware update.
  13. After the firmware update is done, go back to the CMD and type "rename oemxx.inf.bak oemxx.inf" (Again please substitute xx correspondingly).
  • Option B will not work on some versions of Windows (I've tested on Windows 10 Pro and confirmed it does not work), because Windows simply replaces the renamed driver file. However, the suggestion below of going to the Properties in Device Manager, and updating the driver with the installed version of the Lego Mindstorm NXT device driver works great.
    – devhammer
    Mar 26, 2016 at 0:10

I had same issue with Windows 7. I double clicked on the "Bossa Program Port" driver and pressed "update driver", then selected the "LEGO MINDSTORMS NXT Firmware Update Mode" driver instead. Then it was possible to connect to "LEGO MINDSTORMS NXT 2.0" and update firmware.

Original source of information: https://home.et.utwente.nl/slootenvanf/2016/04/15/lego-firmware/

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