Internal Call Static

[MJSD333]

Hello,
I have a customer with a CICS with 6.1 software. When you do an internal call extension to extension you here a low pitched static in the back ground. It doesn't bother enough to cause the parties to not here each other,but is loud enough to annoy you. It does happen on some external calls coming in on the trunks. Four analog lines. It is always there on internal calls. I tried moving the power cord away from the tails as much as possible thinking it might be inductively picking up some AC hum. Didn't work. Tried a reboot that didn't work. Tested the power plug and it is wired correctly. Anyone run into this?
Dmac,

 

[jiniguez]

I would start your test with your analog lines. Put your but set on the lines before the switch and see if you get the noise. If not you can dismiss the Telco. Next I would check your switch tails and make sure they have not come loose on either end. Maybe punch a dummy block and use a Tstar to test the ports and see if you can duplicate the noise this will test your KSU/Station ports.

I know it sounds like alot but you could be surprised at what you find. Alot of problems are usually hardware vice software.

 

[MJSD333]

jiniguez,
Thanks for the reply. I checked the lines by isolateing them from the equipment at the MPOE. No static. I unplugged and plugged the tails back in when I did the reboot. I think it might be the AC plug that it is plugged into. Maybe a ground problem. I couldn't unplug it again and try a different plug, to many calls.
Dmac,

 

[hawks]

what type of phones are they using and does this happen on all sets?

 

[skippy440]

I have seen this problem before (in a CICS 6.0 though). After troubleshooting, a defective CICS KSU cabinet was replaced.

One question though, is this internal static between certain sets or is it random system wide. If it appears to be between a couple of sets only, try diasabling the port to the offending sets (putting these sets 'in maintanance') for 5-10 minutes.

 

[MJSD333]

The phones are, One 7316 no E. And the rest are 7208's. It is on all sets. Didn't try the port disabling,have to try it. Thanks for the replys.
Dmac,

 

[senk1s]

under maintence, you try the bert test on the extension in question ...

is it on all phones?

 

[MJSD333]

Hello,
Just wanted to let everyone know that I got a fix for this.
I got an adapter to go from a three prong to a two prong plug for the power. Made a ground from the adapter which has a ground lug on it. Went from ground lug to metal screw on the backboard. Plugged it into the outlet,plugged the CICS into the adapter and tested. No more static on calls. The house ground was introducing noise to the CICS.
Dmac,