I doubt what you said is standby mode. Is power light on? If don't like, simply disable it....

I think your adapter is broken, why not mail the support and change a new one?

cinar wrote I have exactly the same problem.I can acces internet only with ethernet cable.It looks connected to wifi but nothing comes to browser. I don't have any digisender thing.How can I find...

I think you can see the link, can pair 8 TL-PA211. http://www.tp-link.com/en/article/?faqid=434

The link below may help you, it seems TL-PA411 is more worth to purchase than TL-PA511. http://www.tp-link.com/en/article/?faqid=461