Worldcall internet problem on Tenda Router

My cousin bought Tenda router W268R it works fine on Ptcl and Maxcom but on Worldcall internet it works fine until it disconnects from the power after restarting it shows no internet access and triangle sign on signal bar (windows-7) no internet access.....he has two different connection in same house two different modem giving same problem but working fine On ptcl and maxcom...

now its giving limited access to me on ptcl.....something wrong with this router