I am trying to fix my soft-bricked phone that's stuck in a bootloop. Phone was rooted and working fine until I flashed an incompatible TWRP recovery through Flashify and rebooted. I've Googled for weeks and put up a few other related posts here asking for help but haven't gotten much traction. I do have a backup of the stock recovery in .IMG format, as well as a complete Nandroid system image, also in .IMG format.
With those, I figure I should be able to re-flash it and be done, but that would be too simple. ADB debugging was enabled on the phone before it broke, but ADB commands are out since it doesn't make it far enough in the bootloop to connect to my PC. Fastboot works. If I remove the battery from the phone and plug in the USB it boots directly into fastboot. Device manager lists it under Android phone: Android ADB interface, and some fastboot commands work. fastboot devices returns my phones info, and fastboot reboot bootloader will reboot the phone back into fastboot. Anything else however, is a no-go. I've tried fastboot erase recovery, fastboot boot recovery.img, fastboot flash recovery recovery.img, etc.
All either hang (i've waited up to an hour) or give me the error "command write failed (no error)". I've tried Googling the error and haven't found a concrete answer on what it means or how to fix it.
So far I have tried:
Running fastboot from a command window with admin privileges.
Five different USB cables.
Used every USB port on my PC (at least two, if not all of them are USB 2.0. I know fastboot doesn't like 1.0 or 3.0 ports.)
Using the latest version of fastboot.
Tried a slew of different drivers for the phone (at least seven).
Tried using three different OS's (Win 8, Win 8.1, and Ubuntu).
Tried a few different fastboot GUIs just to make sure I was getting the commands right.
All to no avail. The only thing I haven't tried is another PC and that's only because I din't have one. So, bottom line, the only two ways to unbrick the phone without some special piece of hardware are ADB commands or something that relies on ADB connectivity like SP phone tool or QFIL, or by fastboot comands. ADBs out and fastboot won't play nice. At this point i'm tempted to have a round of phone V. blender. Seriously though, i'm out of ideas. If anyone sees anything I haven't thought of please let me know.