Cannot read Vietnamese, can write in English? Or contact the local support for help.

Could you please share the model number of the powerline adapters? First can connect your PC to the powerline adapter directly and make sure the adapters are still working. If not, maybe you need to...

Refer to this link: http://www.tp-link.com/en/faq-107.html

The port for the page should be 80. If still cannot log in, can try:1. restart the modem 2. clear the cache and history, try other web browsers 3. try wired and wireless connection 4. try different...

Version 11 can only use LAN port in Access Point mode, and the NTP server will not work well in this mode. Seems you can only find a way to provide stable power for it:(

From the description it seems the router died when it drops connection. Did you try reset the router to factory default? If you have tried that and still same issue, it's better to get replacement...