sundance-communications.com/forum Forums TDM Business Telephone Systems Panasonic Telephones & Systems Doorphone Intermediate Problem!

We have a customer having an old TD816 system with a TD160 door controller, a T30865 doorphone and a third party doorstrike installed at the door downstairs.
They have been using this setup for years, and starting 3 months ago, no ringing or whatsoever after their visitors pressed on the doorphone button; visitors have to bang on the door to get someone’s attention sitting upstairs, however, people inside the office can use 551 to talk to the doorphone at the same moment and even use the doorstrike to open the door as well. It is basically an 1-way traffic…! Problem will be only gone after power cycling the KSU.
We replaced a brand new doorphone for the customer 3 months ago, it worked perfectly for the first 2 months and now the same problem came back in these couple weeks.
Does anyone experience this problem before? Can anyone shed some light? TIA!

Sounds like your push buttons are bad, maybe someone has a heavy finger

I would suspect the cable.
Is this a complete cable for the 30865 or are you sharing pairs for the strike?
Either way I would try a different pair for the door phone.
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MrG

I don't believe it would be button as well, as we have just replaced a new one 3 months ago; I was thinking about the cable too, however, if the cable is bad, how come the user can use it to access the doorphone from the office to the door but the visitor can NOT access it from the door to the office all at the same minute of time?!?!? Which I really don't understand, would it the controller instead? Any more thought?
Unfortunately, it is a 2-pair alarm cable, one for the strike and one for the doorphone, no spares... For running a new cable from 2/F down to the 1/F front door would be a tough and ugly one. Cheers!

Calling from the system to the 30865 is more
"forgiving" then pushing the button and trying to cause a short accross the pairs to trip the controller.
Disconnect the connections to the 30865 and short them and see if you can recreate the problem.
If so, then short directly at the input to the controller and see what happens.
Even on a 2 pair alarm cable you can always switch the strike pair with the call pair.
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MrG

Thanks MrG!
But if I swapped the pairs, I mean using the pair with problem connected to the strike; then the problem will go against the strike this time?!

But at least you will have isolated the problem. If so, you can get into the necessary mindset to replace that ugly cable.