Unbricking the UV-K5 V1
Restoring a UV-K5 V1 accidentally flashed with the F4HWN 4.3 Fusion 🔥 Edition firmware, using OpenOCD and a ST-LINK programmer.
Introduction
Some users have accidentally flashed a UV-K5 V1 with the F4HWN 4.3 Fusion 🔥 Edition firmware. This edition is only compatible with:
- UV-K5 V3
- UV-K1
When flashed onto a UV-K5 V1, it causes a complete brick, such as:
- The radio does not power on anymore
- DFU mode is unavailable
- No LED activity
- Flashing tools cannot detect the device
Fortunately, the UV-K5 V1 can be fully restored by using OpenOCD and a ST-LINK programmer.
Requirements
You will need:
- A ST-LINK V2 programmer (original or clone)
- Four Dupont jumper wires
- A small screwdriver to open the radio
- A computer with OpenOCD installed (Windows / macOS / Linux).
SWD connection points on the UV-K5 V1
The radio must be opened to access the front side of the PCB. The UV-K5 V1 exposes a 4-pin SWD (Serial Wire Debug) interface:
| Signal | UV-K5 V1 Pad | ST-LINK Pin |
|---|---|---|
| GND | GND pad | GND |
| SWCLK | SWCLK pad | SWCLK |
| SWDIO | SWDIO pad | SWDIO |
| 3.3V | VCC pad | 3.3V |
Warning
Do not connect the battery while using the ST-LINK. The ST-LINK provides 3.3V to the board.
Installing OpenOCD
macOS (Homebrew)
brew install openocd
Windows
Download the official build from:
Linux (Ubuntu / Debian)
sudo apt install openocd
Verify installation
openocd --version
Download unbrick toolkit
Download the unbrick toolkit archive and extract it on your PC.
Unbrick procedure
Connect the ST-LINK
-
Connect the ST-LINK pins to the SWD pads:
- 3.3V → 3.3V
- SWDIO → SWDIO
- SWCLK → SWCLK
- GND → GND
-
Plug the ST-LINK into your computer.
-
Power on your UV-K5 V1 (normal mode).
Flash the bootloader
From the unbrick_k5_v1 directory:
Option A — Use the helper script
./unbrick_k5_v1.sh
Option B — Run the OpenOCD command manually
openocd -f ./interface/stlink.cfg -f ./target/dp32g030.cfg -c "init; reset halt; uv_flash_bl bootloader.bin; shutdown"
https://github.com/user-attachments/assets/a511fdb3-a3a3-4fe1-91cc-31e765221b22
If no errors appear, the bootloader has been successfully restored.
- Disconnect and remove the ST-LINK from your UV-K5 V1 SWD port
- Reinstall the battery
- Power on the radio on DFU mode
The device should now start correctly on DFU mode again. You can then flash stock firmware, or the F4HWN firmware for UV-K5 V1 (not the Fusion 🔥 Edition).
Disclaimer
This procedure requires opening the device and directly manipulating its microcontroller over SWD. Incorrect use may permanently damage the radio. Proceed at your own risk.