U3-HV not found | LabJack

U3-HV not found

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wplatzer's picture
U3-HV not found


today I connected a new U3-HV device to my Win10 workstation, but it does not work.

Green LED is blinking all the time.

I can see it in the DeviceManager und "LabJack USB Devices" / "LabJack U3". But "LJ Control Panel 2.35" cannot find it.
I installed driver version LabJackBasic-2017-12-20.exe


LabJack Support
labjack support's picture
A continuously blinking LED

A continuously blinking LED indicates the U3-HV is in flash mode, and LJControlPanel will not be able to use it in this state. Flash mode mode is used when upgrading the U3 firmware. A firmware upgrade could of been interrupted, or the U3 had the SPC and FIO5 lines jumpered when it powered up which forces flash mode.

Make sure all LabJack related applications are closed and there are no connections to your U3. Then use our LJSelfUpgrade application to upgrade the firmware to the latest which should get it out of flash mode. Firmware files to use with LJSelfUpgrade can be downloaded from here:


wplatzer's picture
You are right. No firmware

You are right. No firmware was flashed. 

The tool reported:

U3 Firmware Version: 0.000
U3 Bootloader Version: 0.000

After flashing the latest firmware everything is OK.

Best regards,