I experience the same symptoms as , but the proposed solution does not work for me. (the sd_update.log says
dload_sd_ram_data_proc->(retry >= DLOAD_RETRY) failed!
I rooted the phone, and misread the instructions for altering the recovery.img, which is what caused the problem in the fist place.
I have tried flashing with B925, B927 without luck.
I have also tried to use sudo fastboot boot recovery.img with a local recovery.img, and tried flashing fastboot flash recovery recovery.img - but it says
FAILED (remote: Command not allowed)
which i presume is because the bootloader is not unlocked.
I also tried fastboot getvar all - but that came out empty.
I also tried but the model is not listed...
I have an idea that essentially i just have to get in and delete recovery.img and rename recovery.backup.img to recovery.img - but i haven't got a clue about how to do it.
Phone responds to fastboot commands.
I look forward to your input.