SL1100 Lines 1 and 2 Calls Fade out

[HBINGER1]

New SL1100 Install.
Using 5 Analog CO Lines and 6 Digital Sets.
And only happens on CO 1 and CO 2.
Doesn't matter if it's an inbound or outbound call or Handset or Speakerphone.
Happens usually within 2 to 3 minutes of the call.
While talking on the NEC side, they lose the background noise from the far end and think the call has been disconnected.
But the party is still there and sometimes they heard everything, while other times the call sounded like it had jitters.
And now the NEC side has started hearing jitters while listening to the caller on the far end.
I have contacted the Telco. And they show no problems. I verified the Loop Current at 35ma and have even lowered it to 27ma to try and correct.
Also have Calibrated the lines in NEC Programming.
At my wits end. Any help is greatly appreciated.

 

[belevedere]

Swap the cross connect from line 2 to line 3 or 4 (no problems?) then see if it stays with the line. If it moves with the line it's telco.
Another good test on the system side is to cross a SLT port to the trunk port to simulate dial tone and test.

 

[Apersons]

There is a side tone audio setup that you can do to help clear the issues. I don't remember the procedure, might be able to find it online. i also know a good old fashsioned reboot solves a lot of issues well. Might check your connections into the phone system. Make sure no shorts or bad pairs exist.

 

[Ragnorak]

Try unchecking 14-02-24 on all the lines even though the setting seems like it ought not apply.

 

[HBINGER1]

Thanks guys
Tried swapping cross connects and no change. Problem stays on 1 and 2
Did the reboot again and no change
I'll try Apersons and Ragnorak solutions this Friday when I go back

After reading these thoughts my mind went back a few years on a DSX40 that had similar issues.
Turned out to be bad crimps on the RJ45 Mod Ends from the factory Amp Tail I bought.
I'll let you know what happens

 

[Ragnorak]

The "Use Call Waiting Caller ID" setting in 14-02-24 is known NEC bug. It doesn't happen all the time or with all lines but you get repeated intermittent audio drops exactly like you are describing. I am fairly certain this is your problem.