WE500 won't transmit!

[andre_janew]

I have a WE500 that won't transmit.  I replaced the transmitter element and the handset cord, but it still won't transmit.  Also, the cord and element will work in another 500 set.  It appears to be wired up properly as well.  It receives, dials, rings, but won't transmit.

[unbeldi]

It appears to be wired up properly as well.

Either it is, or it isn't.  If something only appears, I'd check again.   

[Ktownphoneco]

As unbeldi has suggested, double check the wiring with the schematic.    If that's OK, check the contact springs inside the transmitter cavity of the handset, and make sure they are (A) positioned correctly to contact the 2 contact rings on the transmitter cartridge, and (B), check to make sure they haven't been pushed or bent down to the point that they aren't actually contacting the transmitter cartridge once it's installed with the cap in place.

Jeff Lamb

[andre_janew]

I'll double check the wiring and check the contacts in the transmitter cup.  If those check out, then what?

[paul-f]

Check continuity of the internal wiring -- wire by wire.  I've found a few cases where the spade tips are not electrically connected to the wires, but are held on by the insulation. The wires had separated due to flexing over the years.  Everything looks right, but as they say, "Looks aren't everything!"

[RotarDad]

As Paul-F mentioned, I too have seen spade lug connections looking good physically, but inconsistent electrically.  If you find one with your ohm meter that is not making a good connection, you may be able to fix it by simply hitting the lug again with the crimper pliers.   I try to keep things original, so if I can tighten the crimp and get the wire to work reliably, I'm happier with the result.   If I remember correctly, I've mostly seen this issue with the smaller gauge handset and line cord wires.  The cloth ringer, dial, and switchhook wires on an old 500 seem to be more reliable.

[andre_janew]

I have a few pictures of what I have.  You can see how the wires are hooked up.  The transmitter cup is clear and you can see that the contacts are doing what they are supposed to do.  I've even taken the handset and handset cord off this phone, put it on another 500 set, and it will transmit with the other set!

[G-Man]

Take a short piece of wire and while listening with the handset off-hook, short terminals "R" and "B". If you do not hear a click each time you short them then there is a bad connection between (iirc) the 22-Ohm resistor and "B" terminal or induction coil. 

You can also temporarily connect the transmitter (and cup) with two pieces of wire directly to those terminals to see if you can hear your sidetone.

[andre_janew]

I do hear a click when I short terminals "R" and "B".  It happens every time I do it.  I have also discovered that if I run a jumper wire from the "A" terminal to the "B" terminal, it will transmit.  It might mean something, but I'm not sure what.

[G-Man]

I do hear a click when I short terminals "R" and "B".  It happens every time I do it.  I have also discovered that if I run a jumper wire from the "A" terminal to the "B" terminal, it will transmit.  It might mean something, but I'm not sure what.

If they are loud clicks (not faint) then the network should be ok. You should not hear anything while connecting to the "A" terminal except for perhaps a very faint sound from it feeding back through the ringer coils to the other side of the line so disregard it.

Try connecting the red and black wires from a known good handset or transmitter cup to the "R" and "B" terminals. See if you can hear yourself on the old handset while talking into transmitter of the good handset and cord.

[G-Man]

To provide you with a clearer understanding as to what we are dealing with...

[andre_janew]

I can hear myself when I have another handset hooked up like you described.  With the wire running from "A" to "B" it now transmits.  Now I am wondering if the ringer will still work.  If it does will it still be able to transmit and receive?

[unbeldi]

I do think you should forget about connecting A and B. If anything let it stand as merely a test.  It is not a way to run the telephone.
Only keep remembering that apparently nothing is wrong with the wiring and the elements of the handset.

The way Western Electric draws the diagram of a 425 network is not terribly instructive about the functioning of the telephone circuit.  Quite the opposite actually, it is rather obfuscating. It is great however in creating very compact diagrams, it is used as a 'black box'-type building block.

Here is a circuit diagram of a complete 500D telephone set with all connecting points and most wire colors shown as well. Being a circuit diagram (not a wiring diagram) it doesn't follow exactly the routing of wires, but emphasizes the electric functioning. It breaks down the complex components, such as induction coil and hookswitch pileup, into its components logically arranged by function.  Note that no two connection cross over each other, simplifying the tracing of current flow.  By comparison with one of WECo's wiring diagrams it should not be too hard to recognize the components.

[andre_janew]

I suppose this means I'll need to get a capacitor if I want this phone to transmit.  Is that what I need to do?

[poplar1]

Those potted networks rarely go bad. You may have already tried this, but, if not:
Swap the entire handset and cord with the handset and cord of another 500-series phone. See if the trouble is now on this pictured phone (with a new handset), or on the phone that was the donor for the handset (which phone now has the pictured handset).