Thanks for replying! While no one should open up televisions and change wifi-modules, it might be the last choice if it happens after the warranty period. I hope some nerd will make a manual to e.g. www.ifixit.com.
20 screws doesn't sound impossible. I'm a noob, but have been able to change old iBook that had also dozens of screws..
So, Samsung seems to have a series of bad wifi-modules.. Perhaps with non updatable firmware. It seemed like a bug that wi-fi settings couldn't be reset properly in the options.
I hope someone at samsung would read this and come up with a proper answer. What if you use the tv with a cable for 3 years and then you move to another flat and start using wifi and it doesn't work.
It's now up to Samsung to step up and show that they care at least a little bit about customer satisfaction and their image. My feeling is that they just make mediocre software, bad remotes with 80's design. They have an arrogant image and I hope they come to their senses.