It is possible to update via PC, including some interesting mods to the built-in CAM which I haven't dared but would like to. If anyone has simple step by step instructions how to render the built in Irdeto to an 'All CAM' I would love to know.
The OTA loader on your Humax will automatically detect if there is an update for your box everytime your box is switched on. If it is unable to detect one then an update isn't being transmitted.
Correct, and in my experience it does not do 'automatic' either. You have to be quite specifically on the transponder which I gave above, go into menu and update. As far as I know there have not been any OTA updates for yonks.
@Prontopro: The main gist of what I asked above was not for anything illegal, it is not illegal to use a multicam for the purposes of inserting legitimate viewing cards into it. It's just a lot handier to swap cards than CAMs. Now I know that you can also do other things to the 5400 built in CAM but that is another story. My request was for simple instructions to make it a multicam.