@Tihara 

If your ISP is a cable provider the issue is likely MAC binding.  This as well as the solution are explained here.  Should this not help please provide more details such as light status of your Archer AC1750 router, lights on the modem and internet address being displayed in the user interface of the AC1750.

@Tihara 

So the internet address is your Public IP form the ISP.  To retireve it log into the Archer A7 using tplinkwifi.net  and click on Advanced at the top. 

Don't tell us what it is just make sure its not 0.0.0.0 as that mean it is not talking to the ISP, if that is the case then we recomend contacting them to have your modem reprovisioned.  

Next look at the front of the router are either of these lights on or blinking?

If the are not on press and hold this button for two seconds and then check again. 

If that doesn't work let us know and we will give you more steps to investigate 

@Tihara 

There is a possiblity that the product is defective, but it's also possible it is something else.  For us to be able to determine this we would need to complete a bit more troubleshooting.

So the good news is the router seems to be online.  if the wireless lights and the WAN (looks like Saturn) are on that means at the very least they in the right status.  For our further troubleshooting, since you can log into the router please check the following

1.  Do you have internet service on a computer directly connected to the router? 

2.  Long in and click on Advanced > Wireless > Wireless settings

Make sure the Enable Wireless Radio is checked and the the Network Name and Password are what you want to use and click Save.

Click on the 5Ghz selector and repeat the step above.  

Finally in the upper right hand corner click on Reboot. Once the rotuer is back up scan the wireless networks in your area and see if you see either of your network.  Try to connect and test the connection.

3.  Go here to download the latest FW and Follow this FAQ for installing it. 

4.  Let us know the results.

@Tihara 

Ok good that's a step in the right dirrection.  Next question.  Did you name the 5GHz the same as the 2.4GHz or is it diffrent.  The password can be the same but we do recommend different names.