@Phardy 

Hi, welcome to the community.

Is the "AX3000" Deco X50?

How do you plan to connect the Deco AX3000 to the AV600 powerline adapters?

Wait for your reply.

Best regards.

  @Phardy 

Hi, in this way, there are some examples:

If the AV600 is a TL-PA4010P KIT, you can use the pass-through sockets to power on Deco.

Other than that, Deco is also a wireless router, and the following layout also works:

ISP modem--Deco X50---<cable>---TL-PA4010~~~~~~(powerline)~~~~~TL-PA4010-----<cable>---a remote desptop/NAS or Xbox,etc.

If you have more than one Deco X50, the powerline adapters could also be used to establish Ethernet Backhaul among Decos, such as:

ISP modem--Deco X50---<cable>---TL-PA4010~~~~~~(powerline)~~~~~TL-PA4010-----<cable>---another satellite Deco X50

Best regards.

  @Phardy 

Thanks for the update. 

Do you mean something like this:

ISP modem router---<cable>---AV600~~~(powerline)~~~AV600---<cable>--Deco X50

It also works.

But if you plan to add only one Deco, how about adding one more wireless powerline adapter, such as 

https://www.tp-link.com/en/home-networking/powerline/tl-wpa8630p/

Best regards.

  @Phardy 

Hi, Deco X50 can be added behind a powerline adapter.  After the basic setup here(https://www.tp-link.com/en/support/download/deco-x50/#video), it is recommended to set Deco into Access point mode: How to set up Deco to work in Access Point mode

By the way, do you know the model number of the AV600?

If it is TL-(W)PA 4xxx.(TL-WPA4220, for example), It has one or two*100Mbps Ethernet ports, while Deco X50 has gigabit Ethernet ports.

Best regards.

Phardy wrote

  @David-TP thanks

The model number is TL-WPA4220

 

So do I just add deco to the powerline adaptor by the deco app and then set the Deco into access point?

  @Phardy 

Yes.