Firmware update seems to have bricked my D435i - how do I unbrick it?

I received my D435i a week ago, and it seemed to be working, more or less. (On my Windows computer, RealSense Viewer claimed it was plugged into a USB 2.1 port even though it was definitely USB 3, and rate-limited it, but on Linux it correctly identified itself as being connected to a USB 3.2 port.)

However, after updating my Linux system two days ago, when I ran realsense-viewer (which had updated from v2.34.0 to v2.35.0), it indicated that updated firmware (version 5.12.5.0) was available, so I told it to install. However, it failed to install the update, and the camera is no longer working properly. It now identifies itself as a D430, with firmware 5.05.07.00 (I'm not sure what the firmware level it was at before the failed update, but that seems low). RealSense Viewer only shows "Stereo Module" as an available module on the left-hand panel, not the RGB and position sensor that were previously present. Enabling the stereo module just provides a stream of RS2_USB_STATUS_TIMEOUT and "Frames didn't arrived within 5 seconds" messages. Attempts to re-install the firmware gets to 30% (successfully saving a backup .bin file, and switching to recovery mode), and then gives twelve RS2_USB_STATUS_TIMEOUT messages before ending with the error "Recovery device did not connect in time!"

On Windows, plugging in the camera gives the usual "USB device connected" sound, followed by a "USB device disconnected" sound every 3.5 seconds until I unplug the camera again. Attempting to run RealSense Viewer with it plugged in just results in a series of error dialogs which reappear if dismissed.

I can see all the backup files in my home directory; presumably the earliest one is from just before failing to install the firmware update for the first time. I also have an earlier one on my Windows machine from the first time I ran RealSense Viewer after getting the camera, and installed whichever version it recommended. How do I restore one of these .bin files to the camera?