@Bips Good day,
If only power led lights up after you set up RE, please try suggestions here:
1>Please verify your Wi-Fi password by forgetting your Wi-Fi network on cell phone first :
Go to Settings-> WiFi on your phone, Tap (or Long press the router's WiFi name ->Forget / Delete the network
Please reconnect to your router wifi and it will ask for a password, will it accept your router password?
2> factory reset tp-link range extender : press the reset hole for 10 secs with RE powered on
On cell phone WIFI settings, connect to Range extender WiFi first ( do not connect to router wifi or and turn off mobile data)
3> Follow instructions on Tether app or Web page step by step ( carefully examine the Wi-Fi password you have put in, and it is recommended to create a different SSID/WiFi name for RE )
How to log into the web management page of the range extender (new logo)?