FYI, I had this issue for at least a year+ and didn't have time to mess with it until now.
HERE'S WHAT I DID.
Started with Software 5-0-0-2318 (probably is what shipped on it in 2015)
Tried to update to 5-1-1-4983 and kept getting system busy try again.
![Huh? ???](http://www.obitalk.com/forum/Smileys/default/huh.gif)
Bought the $15 support via amazon. Tried 5-1-1-4983....still no go
![Huh? ???](http://www.obitalk.com/forum/Smileys/default/huh.gif)
Found this thread
![Grin ;D](http://www.obitalk.com/forum/Smileys/default/grin.gif)
Downloaded 5-0-0-2436 and successfully installed it.
![Smiley :)](http://www.obitalk.com/forum/Smileys/default/smiley.gif)
Tried 5-1-1-4983....still no go
![Huh? ???](http://www.obitalk.com/forum/Smileys/default/huh.gif)
Downloaded 5-0-0-3497 and successfully installed it.
![Smiley :)](http://www.obitalk.com/forum/Smileys/default/smiley.gif)
Tried 5-1-1-4983....AND BAM! It upgraded and google voice successfully updated and is working great.
![Smiley :)](http://www.obitalk.com/forum/Smileys/default/smiley.gif)
Might have wasted $15 but IDK as long as this is working