From what I remember, average phone line will have 4 wires. Blue and white/blue are used traditionally as primary, Orange and White/Orange traditionally used as secondary (might have gotten the colours wrong here but I don’t think so. There is a Blue ‘pair’ and an Orange ‘pair’ either way)
When I say traditionally I mean by BT/Openreach over the years once they changed over to System X and new wiring in the 80s.
Phone line will only use the Blue pair and the Orange pair is snipped back and ignored ‘unless’ a second phone line is used or the Blue pair has a fault and instead of exchanging the cable to the house they just use the other pair which is presumably good.
So, point being your A and B will be a Blue Pair unless it’s not and it’s an Orange pair. This is located at the very back of the socket plate and yes, is property of Openreach but hey… sometimes you just need to look for decorating purposes, right?
This differs from your standard (Cat 3 I think?) telephone cable which is used for extensions and can be 4 or 6 wire all depending what you buy and is a multitude all depending on if you got solid core or stranded. It should be solid core, but as the internal extensions are the customer’s jurisdiction who knows what you’ll find. Some people use Cat5/5E/6.
Anyway. If an Openreach engineer came out to you, then they usually know whether the line is working or not before they get to your house as they stopped off at the local cabinet and/or Exchange and tested. If they need to they will test from the house.
If it was an EE Engineer not Openreach — no ideas who they are but they aren’t engineers by what I have heard, and they are hardly functioning adults by what I have heard… so make sure they are Openreach or and Openreach contractor and not Geek Squad or whatever the heck they call themselves and BT and EE employ.
as for not knowing what comes into the property that’s not entirely true as the A and B on master socket will line up with what is on the other end… because as far as I can remember it actually makes no difference which way round they go. You can put them on the wrong way round and they will still work as they router works out which is which out of pin 2 and 5, which is send and receive. And if the customer has a small junction box on the windowsill like I do, a hangover from the old GPO 746 days, then you can see what wires come from the pole/ground to the internal wiring as well. If not then the Master Socket is normally on an outside wall and therefore is wired directly.
not sure what all the arguing is about. The answer is no, it is unlikely is it wired up wrong unless you let the cowboys at it. Have Openreach out specifically to test the line is necessary. But it’s more likely that something else is wrong, if anything actually is.
