As no else has yet done this, here we go.
To root the ZVJ Baseband, you MUST start from a rooted version of ZVD or ZVH.
Nothing else will work as of now.
This file was supplied by eps1lon3 (click his name to go to the post to thank him!) so a HUGE thanks goes out !! I have simply changed the file name so it is ready to flash, and uploaded it to a site that does not need a subscription to download.
ZVJ Update.zip Download, MIRROR
This will need to be placed on the root of the SD card (not in any folder) prior to flashing via stock recovery as part of the guide linked below. Do not rename or modify.
The new baseband ZVJ has been released and is a fixed (supposedly) version of the failed ZVH update released last September. It is 2.3.3 Gingerbread, and there is no direct root method. Jstntp (click his name to link to thank him!) has successfully found a backdoor root that was previously used to root ZVH before a direct root method was found.
Sfhub's thread to root will be used. Follow all directions EXCEPT #4 and follow directions below.
Note: Please follow all steps from sfhub's thread except #4 which is substituted below. ALL steps are important.
[How-To] Rooting LS670ZVH (+ links to root ZVD/ZV9)
Below is the slight modification to root ZVJ, which is simply substituting the new update.zip for the old ZVJ one.
[BOX="Modified from sfhub's thread"]4) Apply the ZVJ update.zip
The previous step should have booted you into the VH recovery.
From the VH recovery
Press [Vol Dwn] button once to highlight "apply sdcard:update.zip"
Press the [Menu] button to run the ZVJ updater
After around 75 seconds (based on class 6 sdcard) it will return to the recovery menu
If you get a signature error, either you don't have stock recovery (see Step #3) or your ZVJ update.zip download is corrupted.
At this point you need to press the [Menu] button to continue the rest of the install (write the radio, boot android, recreate dalvik-cache).
This should take anywhere from 3-5 minutes. Your phone will reboot. When the update is done, you should be booted into Android. You are now running ZVJwith ZVJ Radio.
If anyone feels I have stepped on toes or not given credit where do, let me know and I will either modify or take the thread down.
Thanks and Credits go to:
eps1lon3 for providing the much needed ZVJ update.zip
jstntp for discovering a working root method
sfhub for the the initial ZVH root method
scrosler for the mirror on the update.zip
All of Team Hydro for the enormity of all thier work.
And of course the Android Central community as a whole, and all its great members.