Check out the entry on this forum page for,.... Problem Upgrading To Ver 1.9 At the bottom of the posting, I'm the JTV Tech here at Line 6, I posted a link for a procedure document I created, that we use here at Line 6 for updating Flash.
No, didn't brick it just yet,.... (error 8000900C) is a hardware run-time error, there was an interruption on the line (data error, slight volt sag, hardware time-out). This can occur at any stage of the connection path between Monkey and the JTV, with all that is in the connection path. So no,.... it's not dead yet.
Double check your set-up and hook-ups to and from computer, any MIDI, the JTV interface box and whatever else you have hooked in.
Then try using the procedure in the link, and if needed,... run it twice. If that doesn't work, then you may have brick the Main Board. A
local authorized Line 6 service center would be able to deal with that.
-P.B. Sarkissian