RJ11 to BT plug issues

[stealthwolf]

We have Samsung KP-DCS 12-B telephones at work. A few have stopped working and our only solution was to upgrade the whole system to the latest one. I ended up buying a few replacement handsets from ebay. I checked all three (as they were used models) by using them on my phone line and they all work.

Two phones have worked fine. The third one doesn't. The telephones have an RJ11->BT plug. This plugs into a BT->RJ45 adaptor which connects to a wall socket. I've played around with the ebay phone and my own. The problem seems to be with the RJ11->BT cable.

I thought it was a faulty one so bought one from B&Q but this also doesn't work.

Any thoughts?

 

[omega015]

Those RJ11 cables can have different wiring configs in them so its a bit hit/miss which work with each handset. You might need to try a few different places to buy them and look closely at the connectors and work out their wiring config (you should be able to see the colour inside both ends) so you can exclude the ones you already have and get the same as the others cables that work. (assuming I understood your post correctly )

EDIT: alternatively you can get the connectors/crimps and make your own cable but that might be a bit of a hassle.

 

[stealthwolf]

Yup I've looked and the pinouts on the RJ11 are opposite to the phone that works. I can't see the BT end unless I break off the plug.

I've ordered a replacement cable off ebay and also a crossover adaptor to see if that works.

Failing all that, I'm going to manually rewire. If I can.

 

[omega015]

Sometimes I find that if you have a lamp or decently lit room, you can just about make out the colour of the wire at each pin on the BT end.

See below for an example of where I usually work out the wiring. Maybe not all connectors have this ability though

 

[stealthwolf]

On the one I bought from B&Q:
RJ11: BRGY
BT: RBYG

On the one that works (from my phone):
RJ11: YGRB
BT: BRGY

On the one that doesn't work:
RJ11: BRGY
BT: GYxx - can't tell easily as there's lots plastic in the way

 

[omega015]

If you cant get one and you need as a quick work around, if you have a spare RJ45 faceplate with 2 x sockets, you can use those to "rewire" the pins and put one end of the RJ11 in one side, then an RJ11>RJ11 cable in the other side and then to the phone. Or purchase an RJ11 coupler, open it up and rewire it inside (and then use an RJ11>RJ11 cable between that and the phone)