Topology you use? Is it internet---1st_7510(AP mode))))))))))((((((((2nd_7510(Client mode)?
Can you see the root AP's SSID in the Client devices? Can you PING the 1st_7510 in 2nd_7510?
Can the device connect directly to the 1st_7510 get access to internet?
Can your computer obtain IP address? What's the default gateway?

Hi
I use same configuration from the beginning, same internet provider, everything its same
From 2nd 7510N Client mode, i find and i connect to 1st 7510N Access Point mode
From beginning 7510N Access Point device connect in Router, now i try direct from internet,but same problem yet
Thanks for replay

Can you do the below tests to see whether the problem caused by router or by ISP?
1. Wired connect the PC to router and try if it gets access to internet? If not, take the action_2 and look at the IP address and default gateway on your PC.
2. Connect your PC directly to internet port and try if you can go online.

FidanBegolli wrote

now i try direct from internet,but same problem yet

@stupidbird when he posted on #3 whats quoted, it was very clear was his ISP

danymarc wrote

@stupidbird when he posted on #3 whats quoted, it was very clear was his ISP

That's what I confused for. I don't know what he mean is connect the PC to router and then internet or he connect the PC directly to the internet port.
As we may all know that PC can connect directly to the internet port, I met someone mistakes that a router is needed between internet port and PC.

stupidbird wrote

That's what I confused for

I understand that is frustrating to have a issue in your Network, a great percentage of people coming to the forum for help come from telephone support, and they think this is Tp-Link support, that people here are hired and get paid, reason why that great percentage don't post all the info need it, to understand the deploy and the issue, reason why in many of my answers I posted this is not a guessing game

That's why we become so cautious and we have to ask so many question to get more important detailed information.
However, they always doesn't answer us directly.

Since 2 years i use same like photo #3
But now i try all method 1,2,3,4

@FidanBegolli if you had #3 working, stick to #3
A good test would be, if you have a 5Ghz device, that you connected to AP before the issue, post if you can connect and surf to AP, that will norrow your issue to Client.
the problem I remember with this device, people that had it, they could not connect with iPhones to 7510 an AP mode, no idea if Android or 5Ghz lap can connect, never liked, never bought it, but lots of smart Mexicans As, bought or someone smarter than them, sold them, making this As believe, this was a 2.4 Ghz device, it was a good laugh, when they told they had spend all night setting 7510 to connect to their ISP 2.4 Ghz router

I was talking to before 1 month (image #3)
But now it does not work in any method