hi can any one help? I have put in a new telephone extension cable upstairs (previous cable connector was unstable) problem is when both upstairs and downstairs phoned are connected in the master box upstairs phone will not work (no dialling tone ) when only upstairs phone is connected works perfectly .When downstairs phone is connected works perfectly only when both are connected the upstairs phone will not work at all .Any suggestions. Do I need a filter on the main connection box.
Phone is for my 88 year old mother so need it working as soon as possible