KN990 Firmware upgrade

| enero 27, 2019

KN-990 Firmware upgrade

Get a Windows computer with Internet access.
2. Download the upgrade tool «KN990 upgrade tool».
Web page download kn/kn990/KN990升级工具V2.exe
QQ group sharing download: group number 124321052.
3. Prepare a square port USB cable (USB-B, printer USB cable).
4. Prepare a usb flash drive.

Upgrade steps:
1. Enter SETTING-SYSTEM-CONFIG-Export to USB Disk.
Since upgrading firmware will forces a factory recovery one time, the configuration must be exported manually to avoid missing previous Settings.

2. Run the upgrade tool and wait for the latest version to be automatically obtained.

KN990 Firmware upgrade

3. Use square USB cable to connect the radio to computer, and choose the serial port number.
If you can’t find the serial port number of the radio station, you can check in the device manager of Windows whether it is because the CH340 driver is not installed. The driver has been uploaded by many users in the group file, so you can have a try. If all goes well, the upgrade tool will display a green square.


At this point, the upgrade tool interface can get the local version number of your radio.

5. Click the «Start» button of the upgrade tool. After a moment, the upgrade tool and the progress bar of the radio start to move.

6. After the upgrade is completed, the station will automatically restart and forcibly restore the factory settings, enter setting-systems-config-import from U Disk, and the upgrade is completed

Upgrade failed:

If the upgrade process is interrupted due to power failure, poor USB contact, computer crash and other unexpected circumstances, then the radio station will not be able to start up normally (become a brick), and the upgrade cannot be resumed according to the above steps, please follow the following steps to save the machine.

1. Cut off the power of the radio station and force it to shut down.
2. Close the upgrade tool than reopen it.
3. Plug in the radio power supply and use the square USB cable to connect the radio to computer.
4. Hold down the last key on the right side of the sub-screen button at the bottom of the front panel of the radio station (shown in the figure below, as shown in the blue circle), at the same time click the power button quickly (note that it is a quick click, do not hold down or hold for too long).

At this point, the radio will be forced into a bootstrap program, and the interface is shown as follows:

5. Select serial port number for upgrade tool.
6. If the serial port number is selected, the firmware version of the radio station is read and the green square is displayed, which indicate that the connection is successful, then click “Start”. If the firmware of the radio station is not read normally, please go back to step 1 and Start again.
7. Wait patiently for the progress bar to finish after upgrading.
Note: no matter what happens in the normal upgrade process, you can use the above steps to save the plane. It would never become bricks. So please release the upgrade. Don’t worry about it.


KN990 provides interface screenshots.
1. Insert the U disk into the USB2 port on the back of the machine.
2. Insert the USB keyboard into the USB1 port on the back of the machine.
3. Press the PrtSc key on the keyboard (this key is usually on the right of F12).
4. The screenshot needs a few seconds, during which the radio interface will pause to refresh. After the screenshot is completed, the interface will resume to refresh and prompt «complete».
The screenshot file will be saved in the root directory of U disk «kn990. BMP».

Note: the currently captured images are upside down. You can use the drawing tool (Ctrl+A) in windows to select all of them and flip them vertically. There will be color difference between the screenshot color and the actual display color of the radio.

Limitation of VFO scope

The default VFO range of KN990 is 0~150M. For some special requirements. Providing a hidden switch can limit the VFO range to 3~30M.
1. Adjust VFO frequency to 12.345.67.
2. Press and hold the power button to shut down.
3. Press the power button to start up.
4. At this time, the VFO range has become 3~30M.
If you want to revert to the previous VFO range, repeat the steps above.


Version: the Version number of the local firmware.
Hardware: BA6BF, author of Hardware.
Software: Droid Zhang, the author of Software.
Help: display the two-dimensional code of this instruction. After scanning it, you can see this instruction, the language of the instruction and the display language of the machine are consistent.
Upgrade History: display the two-dimensional code of the update log. You can see the updated contents of all versions by scanning the two-dimensional code.

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