Hi Peeps,I have a KXTDA30 with ISDN lines & VOIP gateway to a KXTDA15 installed 3 years & all working fine. Recently X204 has been having a problem on outgoig calls to ISDN lines. The person makes a call & they can hear the called part but that person cannot hear them. So changed the phone KXT7630 but fault still occurs. So changed the telephone system & all its cards but fault still there.No other extensions have this problem. I can change the internal cabling but feel that it is not wiring. Any help much appreciated.