My tp-link wa5210g suddenly stopped. no any led gets on while i connect it to the power lan on poe. it is just off totally.no any configure page is displayed on my computer. no any led becomes on . w

A repeater essentially I'd an extender

Connect the router to the modem with an ethernet cable, CAT 5, 6 or 7. Try amazon.

Read this web page as DHCP is not set-up by default on this router.

FAQ ID 348 How to configure TL WA5110G TL WA5210G as repeater

http://www.tp-link.ae/Resources/document/TL-WA7510N_V1_User_Guide.pdf

may find this page helpful. http://www.dd-wrt.com/wiki/index.php...om_a_Bad_Fl ash Its not for the TP-Link router but the same principle could be applied to you with the correct firmware. Its worked for me on more than a few occasions. Providing you can ping the router via a lan cable then the chances of recovering it are very high.

http://www.tp-link.com/en/support/downloadFiles.aspx?mid=01030301&version=V1&pmodel=TL-WA5210G
Seems a problem with the firmware. Double check if your product is the same as the link above and apply the fix described in the support page.
Top firmware version 09/30/2010. this firmware version will include the previous fixes like LED is not ON. Download the file decompress and execute. Please use a wired connection (CAT5/6 network cable) between your computer and the outdoor device. Do not use the wireless connection and be sure that both devices (source computer and destination AP/router/wireless TP device are powered up at mains (no batteries). Back-up yor settings as a firmware update is possible to erase all your settings.
A bit of trivia:
Your wireless outdoor device is decent but not "50km". For that you need a big comms tower.
Good luck.

it doesn't connect on my cell phone wifi why ????

try to face the antenna to a different direction until you got a good signal first.

Log in to router via browser at: 192.168.1.1
At login and password promt enter
login: admin
password: admin

Navigate from left pane: Advanced setup -> LAN
Enter there you'r new ip: 192.168.2.1
Subnet mask: 255.255.255.0

Save

Turn off the router.
Press and hold small reset button (usually with a pin or pen) for 1 minute.
While still holding the reset button, turn the router back on and keep holding reset button for 30 seconds.
This will completely reset your router. The username/password will be set to default. (Usually Admin/Admin)