Guys,
I managed to unlock the PVR on my C6700, having the newest 3009.2 firmware without doing any firmware downgrade or hack and with very little effort.
HowTo:
- Setup ruSamsungTVCommunicator (http://www.rainerullrich.de/samsung/) and test that the virtual remote control is communicating with the TV - it has two additional buttons than your standard hardware remote!
- Switch of TV
- Access the service menu as usual: Press buttons INFO, MENU, MUTE and POWER subsequently on the "real" remote control
- Start up ruSamsungTVCommunicator, connect it with the TV, press virtual buttons FACTORY and 3SPEED
- Now, the entry "Model" in submenu "Option" is no longer gray - it can now be altered to "C6800" with pressing the right arrow key on the remote after selecting the entry
- Switch off TV.
That's it - the PVR is now ready to use!
I recommend to switch off OTN Support (Service Menu -> "Control" -> "Sub Option" -> "OTN Support" -> Off) to avoid future firmware updates.