You may need to pair the two adapters.
You mean, that I should exchange also the one that wasn't broken?
The Adapters come paired together. There is a button on the Homeplug adapters that you press to start the pairing process. You should be able to use the old topside adapter with the new one on the control card but you must pair them together. If that does not work then you could try the new one on the topside along with the new one on the control board. You can visit the Medialink website they should have instructions on how to pair them.
You were right as always! Now it connects. Later, I'll test if motors works as well.