Princess touchtone some keys wont break dialtone, some do, not reversed.

[dpaynter1066]

Hi everyone, I'm a new member and I have searched the forum but haven seen this problem addressed.

I have a TT princess and the 1,2,3 keys produce dual tones when pressed but wont break dial.

The touchtone pad has a row and column tone matrix,  pressing 1*, 20 or 3#  gives pure column tones of increasing frequency.  Pressing 12, 46, 79 or *# gives pure row tones of increasing frequency.

but only keys 4 thru # will break dial tone. 

I've cleaned the switches on the sides of the touchpad, and now the 1, 2 and 3 keys work sometimes.

Has anyone seen this before?  Is there a fix or adjustment?  If it were a plain phone I could just get another touchpad, but this is a lighted princess dial, and having an illuminated pad is a gimme for me, So I need a princess pad and those don't seem to be as available.
Thanks

[Phonesrfun]

The construction of the early touch tone dials is such that pressing any two keys in the same row or coulumn will produce single row or column tones.

If it is making both tones, the only thing I can think of is that the switch contact for the top row is not making all the way and inserting some resistance.  However, you did state that you have cleaned the contacts.

By the way, dont use a file or an emory board to clean the contacts.  That abrasion will take off the metal contact plating that is there to protect the switch and make it less resistive.  Only use a piece of rough paper, like from a business card or a file folder.

[dpaynter1066]

Good tip Bill.

I had a relay burnishing tool dipped in contact cleaner so hopefully I didnt abrade it away.

The BSP for TT pads says replace at the first sign of trouble, do not attempt repair, but times being what they are, I try.

[HarrySmith]

Hi and welcome to the forum! Be warned, these old phones muliply quickly! I call it "Phoneitis", be sure to keep it away from any other phones

With regards to your issue, I do not know if the Princess is similar but I have disassembled a TT dialpad to clean it with good results, pictures here:
http://www.classicrotaryphones.com/forum/index.php?topic=4432.0
This was my first and only attempt so far but it worked out fine! I figured since it was'nt working to start with I had nothing to lose! Take plenty of pictures and make notes for reassembly. As already stated, be gentle on the contacts. I use electrical contact cleaner liberally on dials and circuit boards etc and have never had an issue as a result so do not be afraid to thoroughly spray it down. I also use cans of compressed air meant for cleaning keybords to dry them.

[GG]

Also clean the contacts on the common switch at the top right corner of the backside of the dial. 

Lastly, if you are on a PBX or a VOIP ATA, it is possible that some early TT dials won't work due to high-frequency harmonics that would otherwise be attenuated over the cable span to the CO on an analog CO line.  I have this issue with an early AE touchtone set (works on the CO line, not on the PBX, needs a capacitor added to absorb those pesky high frequencies).  However that apparently isn't the problem in your case per your report about getting single frequencies on some buttons.

If this particular Princess isn't a 10-button set or some other relatively rare version, it might be worth considering as a "display only" model rather than a working one, since Princesses are still fairly common. 

[Adam]

Also, you commented rightly that the translucent Princess touch tone pads don't come up that often, but perhaps you can find a "junker" Princess phone for as cheap as you might hope to pay for the touch tone pad itself, and use the touch tone pad from it to replace yours...

I've done that in the past to get a Princess rotary dial I needed.

Or, here's another idea:  Translucent Princess touch tone pads from that era are identical to the regular grey ones except for the top plastic pieces.  You could take apart a regular touch tone pad and yours, and put the translucent parts on the other, working touch tone pad.

The trick to reassembling a touch tone pad: Sit the plastic frame of the touch tone pad upside down on the top of an empty 2500 set body.  That acts as a "jig" to hold the frame of the touch tone pad while you reinsert the buttons, then the springs inside the buttons, then reattach the back metal base with the associated contacts and pc board.

[Weco355aman]

Hi I'm willing to bet that the TT pad is off frequency and needs adjustment.

[jsowers]

Steve Hilsz repairs TT pads very reasonably, probably for less than you'd pay for a junker Princess when you figure in shipping. He also gives free estimates and comes recommended highly from many Forum members. Here's his page on touchpads...

http://navysalvage.com/tonepad.html


There's a current thread on dial repair where his name is misspelled as Steve Hilz and you can see the testamonials.

http://www.classicrotaryphones.com/forum/index.php?topic=4385.0