atcomsystems.ca/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems CICS extensions have no dial tone

I moved a CICS R1 6.1 sw, one mile for customer relocation and upon connecting, an extension displayed 'alarm 51-2'. That alarm display has cleared but there is no dial tone or intercom on any extension. Buttons 1,2,3 show line 1,2,3 on button inquiry.

I removed and reseated the trunk cartridge with the power off.

The display shows correct time/date on all 3 extensions, and I can browse through programming procedures. Ext displays shows ext numbers 21, 22, 23.

Previous dial tone was POTS & worked fine.
Dial tone is now provided by a new ComCast installation, and 3 ported numbers/lines now check out OK, ANI w/butt set.

Dial tone is now present at the same [labeled] location on the 66 block as before w/POTS lines.

Any help is appreciated.

Happy New Year!

Thanks BayCom

First, measure the on hook DC voltage of the Comcast POTS wanna-bes. If it isn't close to 48 volts, have them reprogram the adapters to the 48 option. Most adapters have it.

I have just tested the on-hook voltage of MY Comcast voice circuit here at home, and it shows 46VDC which is fine for my single line phone. When back on site, how close must the test be to 48VDC for CICS? Could a CICS loss of programming produce such a loss of dial tone, even if other system display behavior appears normal? There is no intercom dial tone, and no battery/circuit-open-sound on any extension, but displays show time/date + lines 1,2,3 on 1,2,3 butttons, then "no service" appears on display with a busy signal.

Thanks for help - Happy 11!

If when you do F*0 and the phones show Lines 1, 2 & 3, then it hasn't defaulted.

Whether lines are actually connected or not you should have I/C tone and you should be able to call (intercom) another extension. Can you?

If not, it's a KSU issue, not a provider issue.

Power down, try another line card and verify the s/w card is properly seated. Then see what happens.

Might be wise to take another KSU with you....sounds like you might need it.

F*0 does display line 01,02,03 for buttons 1,2,3 and time/date displays correctly. I was wondering if some glitch could remove line assignment, but leave lines still showing on display for line buttons - an anomaly has occurred - Ha!

Would the KSU be at fault or the trunk card? ...I don't stock either card.

Sounds more like the KSU to me. If it was me, I'd default it and start from Go. Couldn't hurt to try and definitely less expensive.

Keep us updated on the progress.

I am curious about MooreTel's question, can you press the intercom button and call another station.

At least then you would know if the system is up and maybe you have a dial tone problem.

We ask questions so we can help you out, its good to test what is asked of you.

Sunday 1-02-2011
I haven't been back on site yet due to holidays, but I did mention in my opening post that I have tested for intercom dialtone and there is no intercom dialtone, there is no battery-open circuit sound in the receiver. The extension display is responsive with date/time, and seems to indicate that the system is working properly. F*0 shows lines 01,02,03 on buttons 1,2,4, and other 'button inquiry' seems correct. I can also browse the programming directory and sub-headings like lines, sets, etc ......

When offhook, [no dial tone] select line 1 or 2 or 3, display shows 'no service' then a busy signal becomes audible.

"error 51-2" was displayed on the 1st extension that was connected to an extension port. That error has only displayed that one single time. I have power cycled the system, & reseated the trunk card with power off.

I have not tried replacing KSU or trunk card yet, as those parts are not in stock. I have been hoping the symptoms that I have described would sound familiar to another installer.

Thank you for any help. Happy 11

No dial tone when "off-hook" can be perfectly normal, until a line or intercom button is pressed, depending on programming.

Your error code showing only once on the 1st extension is also normal. Now to find the cause.

I find it hard to believe that you blew a KSU or trunk card in the move I would start by being sure the tails are plugged in securely and be sure you are cross connecting properly


dont worry about how it was connected before , go by the diagram in the manual


until you get ICM DT nothing else matters

how long can the customer go without service ?