Hi, No, it cannot use power from USB.

Hi, It's just one part of the establish of PPPoE connection between the modem and your ISP. They exchange data to negotiate then finish the installation.

Hi, What's the model number? How about hardware and firmware version? What connectivity failure do you encounter? For Unify Hypptv, you need to enter the Internet VLAN ID for internet connection, and...

Hi, Can you explain in English?

Hi, Here's something you can try https://www.tp-link.com/en/faq-2237.html

Hi, As far as I know, there is no repeater or range extender mode on MR3420 V2. How did you setup as repeater? Check firmware version. Update if it's not latest.