Panasonic kx ta624 Ringing Issues

[Mightymegamunch]

Good evening all,

I currently have a Panasonic Kx-ta624 which was running 2 WE 500s happily until today. Slowly all three CO lines have stopped ringing the telephones and the PABX will now only ring digital phones. All other usual phone features (dial tone, dial out and answering phones still work)

Any help would be appreciated otherwise a trip to ebay for a new PABX for me. Thank you

[ka1axy]

First guess would be the ringing supply.
I assume internal calls don't ring the phones either. Check the voltages (challenging without a schematic, but might be possible) on the PCB and start with the external DC supply.

[TelePlay]

A quick check would be to visually look for bad (expanded, leaking or discolored) capacitors and burned resistors on the PCBs.