@JoshN I had to do the same with my S4 If you do a search on eBay for "DC Power Supply Extension Cable Wire 12V for CCTV Camera/DVR/PSU Lead 5M/10M" you will find what you need.

@SMAB I have this same problem with my S4 network. This seems such a basic function of a MESH network, that I am surprised it doesn't work like that!

Good to hear I have two ‘joined’ to my network and they work great.

@TodB If you still have your Airport Expresses, reset them by holding in the button at the back of the Express until you get a yellow flashing light. Then usingAirport Utility, get them to JOIN your...

@Vanellus it's fixed. I reset both Decos and installed the network from new. It only took five minutes.

@Vanellus This is the error I get when I open the Deco app