strange Ground Start trunk problem

[curtismo]

Having a strange issue with CS1000B with a Universal Trunk Card and ground trunks.

We cannot seize an outgoing trunk using a maintenance set on any port on the trunk card. We get about 2 seconds of dial tone then the trunk drops with a TRK017 error. However, at the same time, the AUTO DN destination for the TN indicates a ringing call, but of course the destination DN has "dead air".

Ringing on incoming calls is not detected by the card.

We have tried three other trunk cards, along with rebooting the system and changing slots in the chassis (this is the 4-slot rack mount chassis).

With a buttset we can seize dialtone.

Any ideas on where to head from here?

 

[Curlcom]

Just out of curiosity does the ground your using to start the trunk with your buttset is it common with the ground on the CS1K via your volt ohm meter?

 

[curtismo]

I believe it is a wire attached to the same grounding bar next to the rack.

 

[bdmcdonald99]

Tip / Ring reversal? Check your polarity

It's a phone system, NOT a clock!

 

[curtismo]

Fixed the issue by replacing the chassis with a spare Option 11c cabinet. Believe either the backplane or the power supply was damaged and not switching the ground side correctly. Since we were getting dial tone (MGC/DSP cards) and the co-res CPPM portions were operating correctly, wasn't much else to replace. Discussion with level 2 support at our service provider surmised power supply.

We have been taking lots of lightning storms (and water) in the last two weeks.