Recently we have two routers - one Fritz! Box 7490 in the living room for telephone, laptop and game console as well as a Fritz! Box 7590 in my room for my computer. The former already existed in our old apartment because it was sufficient. We have now connected the latter because the PC is now somewhere else, but both WLAN and LAN do not work. The 7590 should work independently and not only serve as an amplifier. Both have their own DSL connection. How do I get it set up properly?
Simply follow the instructions.
By ordering a second internet connection.
Otherwise they can't establish an independent internet connection.
The connection of the first should also be sufficient for the additional PC in yours. Usually only one supply line leads into an apartment. You can operate a second DSL via this, but it also comes out first (TAE) where the first router is located. For the second, you would have to bring the wiring into your room.