KX-TA824 Dropping Calls

[chimnysweep]

Hi,

Have a KX-TA824 with a 3X8 Expansion card. System has been working great for several years (I'm not original installer). Client called and reported the system was dropping incoming calls if they didn't answer within the first ring.

CO Lines are provided by Cox Cable and they claim that all of their equipment is working fine.

First time I went to troubleshoot problem, I unplugged one of the CO lines from PBX and plugged it into my butt set. Rang multiple times with no problem.

My initial thought was that it was the CallerID module so I removed that and the problem persisted. Decided it was cheap enough to just order a new cabinet.

Transferred the 3X8 expansion card from old cabinet to new one. Uploaded the programming from old PBX to new PBX and the problem persisted. Did a factory reset and reprogrammed new PBX from scratch. Everything worked good until day (four days).

Programming is very basic. Some lines ring immediately and some don't. One jack has a parallel SLT/TAM device plugged in. No AA and no DAY/NIGHT/LUNCH programming.

Now the problem is intermittent. Sometimes the phones ring fine with no issues, other times it rings and drops the call after the first ring.

Could the problem be in the 3X8 expansion card? I think it is probably a KX-TA82483 3x8 Expansion Card and not the KX-TE82483 Hybrid card. Could Cox intermittently be sending us bad CallerID data and confusing the PBX?

We are thinking of gambling on replacing the expansion card but looking for a second opinion.

Thanks,
Westley

 

[WhiteGooner]

If you have put test phone on and its fine, I would take a working switch plug line into that.

Does sound like a equipment prob.

 

[Wanet Telecoms]

Did you say the line comes via cable?.
I have experienced scenarios where a cable with a loose connection gives the same problem. Its fine when there is no incoming call. Until there is an incoming call, it rings once or a few times and disconnects.

However, the fact that you disconnected the line from the PBX and plugged direct into your "butt set" and the line worked without a problem narrows the fault to the PBX side.

Just how many lines are connected, if all is the same thing happening on all line?
If not, try checking with other ports (CO Line ports) and see what happens.

If the problem persists, i would suggest you re-set the unit and re-program it (Do not load the old configuration backup) just incase its in the configuration. Sometimes clients have the tendency of calling multiple techs to log into their system. You never know something could have been tweaked. They never accept the called somebody to login when the machine misbehaves.

Let us know what happens or what you will have done to finaly fix it.

http://www.wanetelecoms.com

 

[Billxx]

I have seen this before.
It sounds like you have what was once called a Breakdown Short Circuit.
That means everything is just fine until Ring Voltage is applied.
A good test is to watch and listen closely when testing.
If the flashing CO Line LED comes on steady for a brief moment and you hear a click (or scratchy click) on your test phone, then you may have this type of trouble.

I do not think the trouble is in your KSU.
Look towards the Extensions instead.
When testing and the trouble is there, unplug a few extensions and then test again.

If the trouble persists, unplug more extensions.
If the trouble disappears, then one of the unplugged Extensions has the trouble on it (or its wiring).

I have found, on the Extension side, wet/corroded jacks (bug spray), crushed mounting cords under a chairs wheels, ant nest, wet phone and leaky AC Duct blowing on a spliced cable in the ceiling.
The cold air condensed on the splice and corroded it into high resistance short circuit.

I have also seen where a computer was plugged into an 8 Pin Jack that went back to an Extension in the KSU.

Let us know if this solved the trouble.

 

[Kierso]

What happens if you ring from and external phones (Mobile phones).
Does it continue to ring on the mobile phones when the extension internally stops ringing?
Or does the mobile get answered?

 

[chimnysweep]

I'm waiting to hear back from the client, but we did agree no news is good news.

Yesterday morning we called Cox and had them turn-off CallerID on all lines. Since then, the problem has not returned. We've been good for about 24 hours.

We'll see how it goes.

Thanks for all the suggestions on where to look!