Just like you I "hate" those that don't search so offcourse I did search.
Could'nt find it (Google 15 min) so i asked it
And by the time he typed that post he could have just told you......
Ok to see the firmware, you need to enter the service menu. Turn the TV on to standby. On the remote press Info, Menu, Mute and then power one after the other.
Look down the page and it will tell you.
One warning about this is it will reset all of your picture settings as it restores back to factory defaults.
Also the standard warning here is be careful in here. Press the wrong thing in here and you could seriously screw up your telly.