@wyattjnr - just to summarise and make sure we haven't missed anything, if you plug a patch cable into your laptop and directly into the hub the laptop can access the internet. If you pug the electrician ethernet cable into the hub and the patch cable into the laptop and socket in the garden room the laptop can not access the internet. I that is correct then the problem must be with the new ethernet cable/socket the electrician installed .
It is possible to wire up the socket & plug wrongly but in most cases even if it is wired non standard if the tester shows no problems it should work. As was suggested earlier you could take the front off your socket and post a closeup picture of the wiring on here which might mean someone can help or you ned to get the electrician back and show him that the laptop and patch cable work directly on the hub but putting his new cable in fails.
I think your best "solution" is to plug the lead, to your garden room, by the router into one of the yellow router sockets and then to try each of the (apparent) five sockets in your garden room with a patch lead and PC laptop. Only one will be connected and should work. The other four are redundant without some kind of powered switch which, I can't believe, the electricians fitted behind the plaster work. I suspect the electrician may think ethernet wiring is like electric wiring. It isn't!
So what you have at the moment is this:
This should work. If it does not either the green cable or the purple cable is faulty.
*To use these the purple cable would need to go from the single socket to a port on a switch. Four more cables then need to connect from the other switch ports to the bank of four sockets.
Have you actually tried the other 4 sockets in case he terminated the cables in incorrect locations?
Buy and Ethernet Cable Tester.
Disconnect the Ethernet cable from the port on the Smart hub and plug that end into one part of the Ethernet Tester.
Take the other part of the Ethernet Cable Tester and plug a small Ethernet patch cable into that then go to the Garden Room and plug the loose end Ethernet Patch Cable that you plug into the Tester and plug it into the Ethernet socket in the Garden room.
Switch on the Ethernet Tester and you should see the sequence of the lights on the tester light up one after the other.
If any of the lights are out of sequence the Ethernet socket has been wired up incorrectly and need to be fixed.
You will see which the number of the wires are that are out of sequence and you will need to place them into the correct sequence within the socket.
If when you plug the tester in nothing lights up it means there is either a complete break in the Ethernet cable from the house or it has been placed into another socket.
Test the other sockets in the block of four one at a time to see if the cable has been terminated there.
What we mean is he might have done something like this:
Hi all!
WE HAVE INTERNET!!
Had the electrician back this morning and because the RJ45 tester was reading backwards from 8-1 rather than 1-8, it became obvious that the wires in the crimped end were the wrong way round!! Simple solution in the end.
Just wanted to say thank you to everyone on here who went out of their way to reply and try and find a solution. Just happy that we now have internet in the garden room and can finally make it a useable room!
Thanks again
Glad you got it sorted and thanks for the update.