After a bit of advice. I recently dusted down my Carrera after a 4 year stint in the shed. Knowing that it had a few issues I dropped it in to my local Halfords store. It required a few things mending with the most relevant to this issue being the rear derailleur.
I get home and decide to go for a quick ride and find that I’m unable to shift gear at all. There isn’t really any tension in the shifters and the chain is currently on the smallest cog. The obvious thing to do would be to drop it back in but if it’s something I’m able to sort then I’d rather get it done myself!
Images below although I’m not sure if it helps in any way.
Thanks in advance