sundance-communications.com/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems trunk card problems

I have a CICS 7.0 that I installed about 7 months ago. I have changed out the trunk card prob about 7 times or more. Something keeps blowing the circuits on trunks 1 and 3. I have checked line voltage on the pots and everything reads normal. I put Oneac surge protectors on all the lines, grounded them back to the power ground and checked for a good ground. Are there any known issues with Nortel with these trunk cards? Does anyone have any other ideas on what to do? Thanks for any input!!

If you are sure you have telco covered, then swap trunks 3 and 4 and see if the problems follows. If so more than likely it really is a CO problem and you may need to get them involved. If the problem remains, then there is something going on in the backplane on the cabinet.

As rusty says move the lines to different ports.

Measurements to take on the line...

Idle voltage, off hook loop current, ringing voltage.

I've had the same problem with a MICS 6.1 over the past year or so. Lines on both of the line card have gone bad at different times. I've tried all the same things you mentioned, plus put a loop current regulator from Mike Sandman on a couple of the lines.

I tested the ac voltage coming in to the surge suppresor and oneac (2 separate devices) and found the minimum and maximum to be just fine. Idle voltage, ringing voltage, off hook, etc. all appear normal.

I changed the ksu out with a new one. Same trouble. Sometimes it lasts 6 weeks, sometimes they call me back the next day with a line out.

The central office is about 2 blocks away. Cable is all in duct and manholes. My telco says there's nothing wrong at their end. The customer's lines appear on different bays in the telco c.o..

I'm at a loss as to what to do next, as you are.
Jim

Do you have to replace the Line cards? Is that port "burned out"? What release are the line cards? I had a CIC's 4.1 with LSDS RLS 1 cards in it and Line 2 kept going dead to the customer. Went to site, ripped off the jumper and BAM, dial tone. It kept happening on Port 202 of the KSU as I swapped Line 2 and 3 and the trouble stayed on port 202. I replacd the line card and that was 8 months ago.

In my case, I have to replace the lsds card to make it work. Before I change the card, there is good dial tone from telco going into the system. At a Norstar set, for the line in questioin, there is no dial tone, or sometimes a noise like a wet, going open pair.

In the beginning I used to power down the Norstar to see if that would help, but it didn't. Now I just change the card. The customer isn't paying for any of this, they beleive it's all under warranty. I'm trying to do good customer service, but I need to put some closure on this soon.

How far did you make the telco go, Yoda? I have had more than my share of "It is not our faults and we have been at the same loss as you state above. I finally tell the customer to take it up with the Telco and guess what, somehow they fix a problem that was NEVER or could NEVER be there problem. Thank goodness for beer and chicken wings!

Yeah, I know how that "no way is it my problem" thing goes. And after a bunch of digging, there's the problem.

I used to work with the guys that are still at telco, years ago, before "downsizing". So I feel like I have a little inside connection, but it's still hard to get some things done. I'll work on it.

Jim

I had this problem back in the day with some copper DID trunks and a CO that was right down the street. After about 18 hours straight baby sitting and telco comming out onsite and telling me everything is within limits. I played around with some resistors in place of bridge clips and found a 100K 1/4 watt resistor did the trick.

I would check the ringing voltage. It should be around 90VAC. 100 max. Anymore and you'll be blowing trunkk cards.