KX-T1232 ringing problem

[JimNY]

Hi Folks,
I have a KX-T1232 that I am setting up to use for my collection. I was able to do the initial programming and wire up a few sets. Everything seems to work as it should (intercom dialing, dial '9' for outside line, incoming trunk calls) except that the stations do not ring. I can hear the relays cycling but it will not ring the connected phones. When I put a meter on the T / R pins I see 20Hz, but only 2 vAC  .

I am hoping there is a simple programming fix, since I am not using proprietary phones, but I can't find anything in the documentation I have found. That leaves me assuming I have a bad power supply or other component that supplies ringing voltage.

I am hoping someone with more experience / knowledge with these units might have some advice regarding troubleshooting/resolution.

Thanks in advance!


 

[5415551212]

I take it you have the manual for it?
I found one here https://www.ask-tsc.com/pdf/KX-TD816.1232.User.Manual.pdf
There are settings where you can change the ring frequency, I highly doubt it produces a sine wave so you'd want to look at that with a oscilloscope as  a multimeter will probably not read the square wave correctly.

[poplar1]

I assume you have only 2 conductors connected to each phone, i.e., the middle 2 pins of the modular station jacks on the phone system. They are usually red and green wires in the cord  for a Western Electric single line phone. The other 2 conductors in the station jack (outside pins) should be connected only for the Panasonic "proprietary" multi-line electronic phones.

20 Hz is right for most single line phones, unless they have harmonic ringers (frequency selective ringers for some party lines).

However, 2 Volts AC is way too low for ringing single line phones. Normally, it is 90 VAC, though some systems use maybe half of that (45 VAC or therabouts).

I don't see the specifications for the ringing output (or any other specs) in the manual index starting on page 383.

[poplar1]

Specs are in the Installation Manual:

https://tenpabx.com/download/panasonic/KX-TD1232/TD816_1232BX_Installation_Manual.pdf

25 Hz should work  fine for "straight line" ringers that are used to 20 Hz from the telephone company central office.

[JimNY]

I do have the manual and saw the spec for ringing voltage. I will keep tinkering and post a resolution if I ever find one. Thanks as usual for the quick replies.

[5415551212]

 What are you using to program it? It does talk about ring volume settings on page 34, I would think those are stored in the phone as some of the phones its a 3 position switch.

However, 2 Volts AC is way too low for ringing single line phones. Normally, it is 90 VAC, though some systems use maybe half of that (45 VAC or therabouts).

The thing is I am not sure a Digital Multi meter would give a meaningful voltage reading as it outputs a simple square wave, not a sine like a key system ring generator that uses a ferroresonant transformer.
These handheld scopes they sell now for ~$120 or even less are really handy for basic troubleshooting electronics in the field but would also be good for a vintage electronics/phone hobbyist, I have a Hantek and it works well there are now even cheaper ones you can get. You could also open up the unit and give it a look over for leaking caps.

[poplar1]

Are any of your phones a Western Electric 302, Automatic Electric 40 or 50, Kellogg 1000, or Stromberg-Carlson 1243?

If so, if you temporarily unscrew the transmitter cap, and remove the transmitter unit, you can listen to the receiver unit (with the handset off hook). There won't be a dial tone. You will be able to hear the 25 Hz ringing current in the receiver when a call comes in.  What you would hear is the actual ringing current.  It should be much louder than the fake ringback tone that a caller would hear when making a call to another extension or to an outside party.

Each station port on the Panasonic has a maximum ringer load of 2 REN (REN = Ringer Equivlence Number, using the ringer in a WE 500  as the standard REN of 1.0.)

Did you purchase the system as New or Used? Did you receive any kind of warranty?

I am using a Panasonic TA824 Key System. On some single line phones, I have to move the ringer biasing spring to the low-tension notch, because the system is not strong enough to signal a ringer in the normal position.

[JimNY]

Hi Folks,
An update to the original post. I did some good old fashioned educated guesses and deduced that the problem was either a transformer or the circuit card that transformer was connected to. Since I only had a spare circuit card I pulled and swapped in the new one and my test phone was suddenly ringing loudly!  Upon inspection of the old card there was a noticeable burn mark around the heat sink.  The transformer plugged into CN51.

Thanks to everyone who replied.