I have a Color LaserJet 4700dtn with a 2005 firmware, and we also had the issue where attempting to upgrade to the newest firmware (46_200_1 at the time of writing this) would issue the error 49.4CF2.
According to this thread:
http://h30499.www3.hp.com/t5/Printers-LaserJet/CLJ-4700-49-4CF2-error/td-p/5293729#.Up9I6uIlh1x
I need to install firmware version lj4700fw_46_120_4.rfu first and then I can install the latest firmware.
The older firmware files used to be located here:
ftp://www.hp.com/pub/networking/software/pfirmware/
But they are not there.
Are the older firmware files available elsewhere? Does anyone have a copy of this older firmware?