Another Panasonic PABX problem. - UK Vintage Radio Repair and Restoration Discussion Forum

oldmoley1 · 11th Oct 2014, 5:48 pm

I've been following with interest, the advice given to Ryan regarding his Panasonic 308 system (glad to see everything is now OK Ryan), and wonder if anyone could help me with a problem I have with a newly-acquired KX-TA 624.
Briefly, I've used a Panasonic programming phone to allocate numbers to each extension port successfully. However, the following is occurring:
a. I'm using the Panasonic phone in port No. 1, and a mixture of GPO/BT Tone and pulse phones in the others.
b. extension to extension calls can be made between all phones EXCEPT dial types.
c. the Panasonic phone on extension 1 rings out, but none of the others do!
d. swapping phones around between ports makes no difference.

I've searched through the programming manual, but can't find any reference to this problem. Are any of you able to shed any light on what might be wrong? I'd be very grateful indeed!

OscarFoxtrot · 11th Oct 2014, 9:53 pm

b. Have you tested the dial phones on the BT line for correct dial pulsing
c. do you have ringing capacitors or are your phones wired for 2-wire operation

Program 120 sets the frequency for ringing phones, default is 25 Hz.

julie_m · 12th Oct 2014, 12:15 am

No ringing definitely sounds as though the phones have been wired up to the PBX using slave rather than master sockets.

Do you see something like 50 - 100 V AC across pins 2 and 5 of the socket of a phone that should be ringing out? If so, does inserting an ADSL filter make the phone ring?

Oldcodger · 12th Oct 2014, 1:22 am

There is a known problem on Panasonic systems with certain sets, mostly with FAX M/C, but possibly with other bits of kit. As said the default is 25 Hz but a lot of BT kit doesn't like this. The fact that the Panasonic phone rings on a port, but others don't, points to this problem.

OscarFoxtrot · 12th Oct 2014, 10:45 am

Quote:

Originally Posted by Oldcodger

The fact that the Panasonic phone rings on a port, but others don't, points to this problem.

I think Panasonic system phones ring from the data signal, not the ringing voltage on the line.

If you plug both into the same port you will find the SLT ringing follows the relay clicking in the PBX, the PT ringing doesn't and isn't in synch with the SLT.

oldmoley1 · 12th Oct 2014, 4:47 pm

Many thanks to all of you for your invaluable advice, which has enabled me to crack the problem. I had the phones connected up via RJ11 to BT type socket cables, and it appears that none of these contained capacitors! The insertion of ADSLs has done the trick, although longer term I shall be wiring up to appropriate BT sockets. The Panasonic phone was completely unaffected by this, so obviously picks up from the data signal as Oscarfoxtrot has said. Just waiting for a deputation from my neighbours demanding why they have heard phones ringing all afternoon!

Only problem now remaining is the loss of my programmed-in settings when the PABX is switched off. I imagine this is due to the lack of a back-up power supply rather than a fault. This won't be too much of a problem since, like Ryan, I am only using it to run part of my phone collection, although I have plans to install extensions around the house.........

Once again, thank you all.

Dave Moll · 12th Oct 2014, 6:05 pm

Quote:

Originally Posted by oldmoley1

Only problem now remaining is the loss of my programmed-in settings when the PABX is switched off.

I have a similar problem with my house exchange (an NTS London 16), presumably as a result of the soldered-in backup battery having been long-dead. I've never bothered to do anything about it as it stays powered up 24/7, and the amount of reprogramming needed after a power outage isn't major. I simply have the reprogramming instructions set out on the label of the master 'phone of the system.

Oldcodger · 13th Oct 2014, 12:26 am

Quote:

Originally Posted by oldmoley1

Only problem now remaining is the loss of my programmed-in settings when the PABX is switched off.

I'd suggest that either the memory retaining battery has failed / is missing / or is not connected. (I'd suggest either of the last two, as I've never seen a back up battery fail) Had a look in my 624 handbook to jog my memory, but to no avail as to it's location. I can't remember what it looks like, but I'd imagine it's similar to the other systems as a heatshrunk unit, of two cylinders approx 15-20 mm with a two wire cable terminated in a white plug.

Pellseinydd · 13th Oct 2014, 11:14 pm

The backup battery is a flat circular button cell soldered to the main 3+8 mother board - only accessible by removing any expansion boards. Can't find any mention of replacing it in the way that it can be done on the previous KXT range

Ian

Oldcodger · 17th Oct 2014, 12:59 am

Quote:

Originally Posted by OscarFoxtrot

I think Panasonic system phones ring from the data signal, not the ringing voltage on the line.
If you plug both into the same port you will find the SLT ringing follows the relay clicking in the PBX, the PT ringing doesn't and isn't in synch with the SLT.

Correct, BUT, I was talking about Panasonic SLT, rather than system phones, which get the data down the system bus to control the functions.
TBH, I've never thought about the function of the analogue pair, but I'd guess it's to provide power for the system phone data system.

smiler411 · 21st Oct 2014, 7:29 am

Panasonic proprietry phones use the outer pair of the RJ45 for data and power and the inner pair for the analogue signal only. The ringing is controlled by data as has been said.

As for SLT ,ringing and loop come down the inner pair so with some phones you will need a master socket to provide the ring signal as you have found out.

11th Oct 2014, 5:48 pm	#1
oldmoley1 Tetrode Join Date: Apr 2014 Location: Northampton, Northants, UK. Posts: 84	Another Panasonic PABX problem. I've been following with interest, the advice given to Ryan regarding his Panasonic 308 system (glad to see everything is now OK Ryan), and wonder if anyone could help me with a problem I have with a newly-acquired KX-TA 624. Briefly, I've used a Panasonic programming phone to allocate numbers to each extension port successfully. However, the following is occurring: a. I'm using the Panasonic phone in port No. 1, and a mixture of GPO/BT Tone and pulse phones in the others. b. extension to extension calls can be made between all phones EXCEPT dial types. c. the Panasonic phone on extension 1 rings out, but none of the others do! d. swapping phones around between ports makes no difference. I've searched through the programming manual, but can't find any reference to this problem. Are any of you able to shed any light on what might be wrong? I'd be very grateful indeed!

11th Oct 2014, 9:53 pm	#2
OscarFoxtrot Heptode Join Date: Apr 2011 Location: Edinburgh, UK. Posts: 805	Re: Another Panasonic PABX problem. b. Have you tested the dial phones on the BT line for correct dial pulsing c. do you have ringing capacitors or are your phones wired for 2-wire operation Program 120 sets the frequency for ringing phones, default is 25 Hz.

12th Oct 2014, 12:15 am	#3
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Another Panasonic PABX problem. No ringing definitely sounds as though the phones have been wired up to the PBX using slave rather than master sockets. Do you see something like 50 - 100 V AC across pins 2 and 5 of the socket of a phone that should be ringing out? If so, does inserting an ADSL filter make the phone ring? __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

12th Oct 2014, 1:22 am	#4
Oldcodger Nonode Join Date: Oct 2014 Location: West Midlands, UK. Posts: 2,181	Re: Another Panasonic PABX problem. There is a known problem on Panasonic systems with certain sets, mostly with FAX M/C, but possibly with other bits of kit. As said the default is 25 Hz but a lot of BT kit doesn't like this. The fact that the Panasonic phone rings on a port, but others don't, points to this problem.

12th Oct 2014, 4:47 pm	#6
oldmoley1 Tetrode Join Date: Apr 2014 Location: Northampton, Northants, UK. Posts: 84	Re: Another Panasonic PABX problem. Many thanks to all of you for your invaluable advice, which has enabled me to crack the problem. I had the phones connected up via RJ11 to BT type socket cables, and it appears that none of these contained capacitors! The insertion of ADSLs has done the trick, although longer term I shall be wiring up to appropriate BT sockets. The Panasonic phone was completely unaffected by this, so obviously picks up from the data signal as Oscarfoxtrot has said. Just waiting for a deputation from my neighbours demanding why they have heard phones ringing all afternoon! Only problem now remaining is the loss of my programmed-in settings when the PABX is switched off. I imagine this is due to the lack of a back-up power supply rather than a fault. This won't be too much of a problem since, like Ryan, I am only using it to run part of my phone collection, although I have plans to install extensions around the house......... Once again, thank you all.

13th Oct 2014, 11:14 pm	#9
Pellseinydd Heptode Join Date: Jul 2007 Location: Flintshire, UK. Posts: 707	Re: Another Panasonic PABX problem. The backup battery is a flat circular button cell soldered to the main 3+8 mother board - only accessible by removing any expansion boards. Can't find any mention of replacing it in the way that it can be done on the previous KXT range Ian Attached Thumbnails

21st Oct 2014, 7:29 am	#11
smiler411 Tetrode Join Date: Apr 2008 Location: Rhondda Cynon Taff, Wales, UK. Posts: 88	Re: Another Panasonic PABX problem. Panasonic proprietry phones use the outer pair of the RJ45 for data and power and the inner pair for the analogue signal only. The ringing is controlled by data as has been said. As for SLT ,ringing and loop come down the inner pair so with some phones you will need a master socket to provide the ring signal as you have found out.