GPO 321 re-wiring for UK

[dglynn]

Hi - I have a GPO 321 ("rams head" wall phone) that I've attempted to re-wire for use on current UK plug-and-socket. Line has been tested with known good phone.

Problem I am having is that the GPO 321 rings when called but when the receiver is lifted, the ringing stops but the line isn't engaged and instead you can hear a buzzing through the receiver in the same pattern as the ringing.

Also, I can't dial out - there is no dial tone audible through the receiver when lifted but when turning the dial slightly, you can hear the faint sound of a dial tone.

I've had this exact same problem with another phone (GPO 312) and I managed to resolve it but can't for the life of me work out how I did it or how I replicate the same on this GPO 321.

I originally followed these instructions:

https://www.britishtelephones.com/pstconv1.htm#321

Remove strap T10 - T11.
Remove strap T12 - T13.
Install a 3.3K ohm resistor between T12 and T13.
Strap T1 - T2 - T8 - T7.
Red wire of line cord to T3.
White wire of line cord to T1.
Blue wire of line cord to T11.
Green wire of the line cord is spare and can be parked on T9.
Rectifier No. 205 (if needed) inserted between T6 & T5.

Didn't bother with the rectifier or resistor for now.

Any ideas?

[tubaman]

Are you sure the line cord you have used correctly corresponds to a BT one - ie red 2 (by plug latch), blue 3 and white 5 ?

Looking at your photo I'd try swapping red and white in the first instance.

[dglynn]

I assumed it was correct but worth ruling out. Will check it.

[dglynn]

Checked the wiring for the line cord and it is correct. Tried swapping red and white line cord connections, but didn't resolve the problem. Also, for good measure, tried swapping red and white receiver cord connections; again didn't work.

Might have to sit in a quiet room with the wiring diagram to work it out.

Any other suggestions gratefully received!

[tubaman]

Looking at your photo you appear to have strap 2-3 missing on the dial terminal block when compared with the diagram?

[dglynn]

I added a strap between 2-3 on the dial terminal block as you suggested and also resolved a loose connection on the dial itself. Works perfectly now. Thanks for the help.