sundance-communications.com Forums Telephony Discussion Phone & VoIP Systems Samsung Telephones & Systems No ring voltage

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?

The super cap is in cabinet 1 from memory.
If the card is in cabinet 3 then it's something in this cabinet.
Dodgy slot or card.
In theory you can just switch that cabinet off, been a long time since I worked on dcs system.
Make sure you have a spare psu unsafe the cabinet doesn't come up after being switched off

Super cap is on the motherboard in cabinet 1. Ring voltage is generated by the sli cards from the regular system voltage -55v and there is a ring generator on each sli card. I don't know if you can shut down 1 cabinet or not, I was always under the impression that the expansion cabinets needed to be on first so the main cabinet would "see them".

Thanks for the info. Sounds like it's the card itself. Maybe that chattering/motorboat noise I'm hearing has something to do with the ring generator on the card. We should still have a few SLIs at the shop.

Probably best to shut the whole system off. And yes I was going to bring a power supply or 2 just in case.