annoying ringing sound on active line when 2nd call rings in

[conleycomm]

My customer has a Partner II R3.1 with Partner VS voice mail R3.1 We have 12 stations and 9 CO lines.

When a station is off hook on an active call, either internal or external, and a second call rings in, the first user hears a ringing sound in their ear, sounds like an old rotary phone with the click, click, click sound... Very annoying. I don't know how to troubleshoot or resolve this situation. Any ideas?

This problem began when I upgraded the processor from a Partner Plus to the Partner II added extensions.

 

[jlshelton]

This sure sounds like a wiring error between the CO lines. Did they change, too? Otherwise, it could be a wiring problem between the extensions; either a short between one conductor of one extension and a conductor of the other extension, or very bad mixing of pair twists. The ringing voltage from one extension is jumping over to the other extension.

If you can, unplug the wires from both phones and the control unit, and check with an ohm meter to see if you have a short. If not, check very carefully that the wires aren't somehow intermingled badly.

 

[conleycomm]

Can you explain why the sound resembles a pulse dial phone instead of hearing actual ringing?

 

[jlshelton]

When ringing is sent to a telephone, a high AC voltage, approximately 90 volts, is sent, usually at 20 Hz (very low frequency.) This is not the same frequency that you hear as the caller. And most phones translate the low-frequency, high-voltage ringing into something else - a chirp, tone, warble, bell, or whatever. But if you were able to answer the phone and still have the ringing continue, you'd hear a very low frequency sound that resembles rotary dialing to a degree. Normally, you'll never hear that, because by answering the phone, you have instructed the Central Office to stop sending the ringing voltage. You can hear this sound if you have a lineman's butt set (test telephone) which can monitor a line without answering it.

Good luck with finding the wiring fault.

 

[conleycomm]

UPDATE: I did some more troubleshooting. I tried some of the suggestions above. I made sure all the wiring was orderly, nothing too crossed up. Made sure phone wiring both station and CO were not entangled with AC wiring of any kind. I noticed the customer's system had not been grounded so I ran a good earth ground to both the main and expansion processor. I one by one removed CO lines and station lines one at a time to see if it made any change in the noise... All of this allowed me to isolate the problem to the first 6 stations. They were the only ones to hear the annoying sound when a second call rang in. I determined that it must be localized to the 206 card. I removed and reseated the card with no improvement so I replaced the 206 card and the problem was solved.

 

[GroundWire]

The problem you were experiencing is present in the power supply of the 206 module you were dealing with.

http://www.refurbsupplies.com

sells those power supplies NEW for $65. The benefit of course is that is the #1 cause of failures with those modules, is the damn power supply.

I've had this problem man times as well, and have resolved it in this manner - Same 206E, new power supply.

Judging from what I've witnessed - I'd say there is a filter capacitor that went out in the power supply unit, and it is allow the ringing part of the supply to affect the voice/talk part of the supply.

Hope this helps!

- Joel