DIAGNOSIS This is usually the printer getting stuck in the initial setup loop. The Wi-Fi module is awake, but the connection handshake isn't completing, often because of a router setting.
FIX First, power cycle everything. 1) Turn the printer off and unplug it for 60 seconds. 2) Restart your router. 3) Plug the printer back in and turn it on. 4) On the printer's control panel, hold the Wi-Fi button for about 3 seconds until it flashes blue. This resets the network settings. 5) Use the Epson Smart Panel app on your phone or computer—it often guides the setup better than the printer's tiny screen.
IF THAT DIDN'T WORK Your router might be using a band (like 5GHz only) or security protocol (WPA3) the ET-2800 can't handle. Log into your router's settings and temporarily create a 2.4GHz network with WPA2 security (no special characters in the network name). Connect the printer to that, then switch back if you need to.
HEADS UP The ET-2800 doesn't have an Ethernet port, so Wi-Fi is your only wireless option. If setup fails repeatedly, the initial printer firmware might be old. You may need to do a temporary USB connection for the first setup so it can update.