Finally made it to the DCS customer I have in a neighboring state. While there, the contact mentioned they're not receiving faxes. Found there's no ring voltage, and a slight constant chattering like sound on the line, along with the other 7. I didn't know about this trouble of else I would have brought an SLI card. I wonder though - does it sound like that or a power supply? If it was in fact a bad power supply in cabinet 1 - would the 'super capacitor' be on circuit board within the cabinet? Hoping so - thinking so as I may have replaced one on a spare system a while back. If that doesn't hold a charge I'd be re-programming the entire system. I also wonder if the ring voltage comes from the power supplies that insert into the cabiner (PS40, or PS60?) or is that voltage generated elsewhere in the cabinet.

For now I connected a spare analog line to the fax and changed the dedicated trunk to ring the new ext. The customer isn't concerned that it's a different ext, but I want replace what ever hardware is bad. The SLI in question is in cabinet 3. I will look in the manual - but off hand I wonder is it necessary to shut the entire system down to replace that SLI, or can I just power down that cabinet?