@LULUN If you can't see the wireless password/PIN clearly on the bottom sticker use an ethernet cable to connect to one of TD-W8961N LAN ports. Open http://tplinkmodem.net or 192.168.1.1 in a browser...

@John_04 Try reducing the RE wireless coverage like this: and test again. If the problem persists lower the coverage to minimum and test again.

@pgn_solution Here's a video on how to setup your RE. There's no need to open ports on a firewall since you install the RE in your LAN and you would connect to the RE from your LAN.

@Ironham Here's a video guide on how to setup RE200. If needed, you can reset the RE200 by its reset button and start the setup again.

@Gicla Yes, the WebGUI is different - I posted a screenshot from Archer VR600. It appears that the FW in question can only be found on the Italian support portal. My advise conract your local tech...

@therock1024 TL-SG105 is an unmanaged gigabit switch. There's no point messing with QoS settings of your router - that's probably a cable issue (switch port doesn't like the ethernet cable you're...