Is there an alternative method such as copying off the sub and then running software from the internal HDD?
No, sorry. We have to tap into the Humax' native firmware update process, and that is triggered by it detecting the proper file name and having specific codes in the data, in a root file on the USB (I guess that could even be an external HDD if you like), at boot.
Have you ever successfully updated the official firmware by the USB process? It's only a case of doing the same thing but with a different file (of the same name).
(These instructions are specifically for the HDR-FOX T2, the HD-FOX isn't quite the same)
1. Make sure the HDR is running the latest official firmware (currently 1.02.20).
2. Make sure you have obtained the custom firmware file for the HDR
not the HD-FOX, and for the correct version of the official firmware.
3. Copy the custom .hdf file to the root directory of a FAT32 USB stick (preferably empty but not essential), and
make certain it is named "
hdr_fox_t2_upgrade.hdf" on the stick.
4. Plug the stick into the HDR and reboot (if rebooting by going in and out of stand-by, give it 30 seconds before turning on again).
5. If the firmware update process does not start, try another stick.
If you have done all that
precisely, and still unsuccessfully, we'll have to think again.