First: download and install this:
http://www.mympxplayer.org/rockchip-...120-df884.html - this is the software to do fw-updates 4 Rockchip-Players.
Second: do follow the dead Recovery Guide to reset your nexus and to notice controlnumber, platenumber and screennumber
Third: ask s1fw in the fw-forum for the right fw by telling him the controlnumber, platenumber and screennumber
Fourth: follow s1fw answered link and download the fw
Fifth: decompress the archiv and start the consumerupdate. Open the *.rfw-file, connect your nexus, start updating