[Station X]

Your phones appear to be wired correctly.

I am puzzled by the fact that dialling out from a phone causes the bells of other phones to tinkle. This should not happen. All bells are wired in parallel via the blue wire of the line cord and the extension wiring it connects to. Dial springs in the phone being dialled from then short out ALL the bells during dialling.

Check that the blue wires of all line cords are connected together via your extension wiring.

Check that dial spring contacts D1 & D2 and D3 & D4 are clean and that they make as soon as the dial is rotated from its normal position.

Check that dial spring contacts D4 & D5 are clean and that they make and break when a digit is dialled.

Check that the dial takes one second to return to its normal position when digit '0' is dialled.

Unplug the phone and connect a meter on ohms range between the red and white wires of the line cord. With the handset on hook you should see infinite resistance. Lift the handset and the reading should drop to a few ohms. Rotate the dial and allow it to return slowly. The reading should oscillate from high to low. If the meter is an analogue one let the dial return at normal speed. The needle should oscillate and its percentage of scale deflection will give you an idea of the mark/space ratio of the dial.