TS-02 — the printer can't see your router
Check the band first, because this is where most Brother setups fail. These machines don't do 5 GHz, so your router needs to be broadcasting 2.4 GHz, either on its own or in mixed mode. If both bands share one network name, the printer can end up hunting for a network it can't join. Beyond that: make sure the router is on, move the printer within a metre or so of it while you set up, and if you've turned on MAC address filtering, add the printer's MAC address to the allowed list.
Related codes: TS-02