@DANIK1956 Click here to get the download link of the firmware for TL-PA4010. Have you tried to upload the NVM file to give it a shot? What will happen then?

@laserbeam Yes, from the led status, all the 3 powerline adapters are working fine. And you can confirm whether you can get internet from them with wired cable connected.

@Vea You are welcome, take your time to give it a shot. Any further problem, please let us know.

@RafaelLomba Thanks for your reply. To help fix this issue, our engineer will email you later. If you are willing to do further troubleshooting, please check your inbox. Thanks for your support and...

@Zyngi Try to disable NAT boost on the web UI of Archer C1200 first. Then you can try to access the HDD via FTP to give it a go. Please show me a picture of the transfer speed as well.

@SandeRF To login to the extender via Tether app, we need connect cellphone to the extender's wifi first. Meanwhile, if the extender still can detect the 5GHz but unable to connect to it, you can try...