RAK4631 solar node not detected after interrupted firmware update

[dorjecito]

Hello,

I have a D5L Solar Node based on RAK19007 + RAK4631.

The node was running Meshtastic 2.6.11.

I started an OTA firmware update from the iOS app to 2.7.15. The update remained at 0% for several minutes, so I removed the batteries and restarted the node.

Current situation:

• Green LED blinks every ~2 seconds.
• Red charging LED works when USB is connected.
• Node no longer appears in the Meshtastic iOS app.
• No Bluetooth advertisement is visible.
• Windows 10 does not detect any USB device.
• macOS does not detect any USB device.
• Tried 5 different USB cables.
• Double-clicking RESET does not expose a UF2 drive.
• No COM port appears.
• No “Unknown USB Device” appears in Device Manager.

The board still appears powered because both LEDs are active.

Has anyone recovered a RAK4631 from this state?

Could the bootloader have been corrupted during the interrupted OTA update?

I can see two green LEDs blinking:

• Green LED on the Keepteen solar board blinks every ~2 seconds.
• Green LED near the RAK4631 reset button blinks continuously.
• Red USB charging LED is solid when USB is connected

Photos attached.

Thanks.