atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telephone Repairs & Equipment Western Electric 2500DM ringer inop

All,
Thank you for reading my post.

I purchased a used Western Electric 2500DM. Everything works fine except it won’t ring. I looked up the wiring diagrams and checked to make sure everything was connected properly. This phone has the four-wire type coil and a 425E net.

The wires from the coil are connected to the net as follows:
Red to L2
Black to L1
Red/Grey to A
Grey to K

The wires from the line in jack are connected as follows:
Red to L2
Green to L1
Yellow to G

Note: The yellow wire from the line-in connects to G but no other wire is connected to G. The jack only has the red and green wires (inner pair) connected from the NID outside the house. So the yellow wire isn’t really connected to anything. I know that there was a fix for other 2500 series phones of moving the black coil wire from G to L1 but mine was already wired that way and if I read the schem. correctly, then it was sent out like that originally.

I tried switching the red and green wires in the jack (E.G. Red to Green & Vise-versa) to eliminate any polarity issue but the phone won’t ring either way.

More modern phones with digital ringers work fine on the jack. This is not a VOIP jack. It is a traditional POTS jack.

With the cover removed, I watched the clapper while calling the phone. It doesn’t even move a little.

I have the ringer adjusted to loud and can move the clapper with my finger. There is a little wire-like device under the clapper that runs the length of the clapper and through a plate that looks like a backwards G. I’ve tried the little wire-like “spring” in what I can only describe as free and captured but still no ring.

Any suggestions on where to look next?

Thanks in advance.

Sounds like your wiring is correct. The "DM" modification provided for straight-line ringing from the factory. I was going to suggest adjusting the bias spring but as I read further into your post, I saw that you tried that.

You may have a bad capacitor between terminals A and K on the network. The easy way to test this (and the ringer coil) is to place both the slate and slate/red coil wires together on either terminal. If this shorts out your phone line, then the coil is good and the capacitor is bad.

I've seen more coils fail than capacitors, but the coils are plentiful and easy to replace.

How many tels. are connected to that line; should have a REN of 5 on the line(ringer equivalance number), the 2500 usually run about 1 to 1.5 and over 5 they won't ring. Have you measured the ringing voltage with the phone disconnected? use a vom meter to test the coils on the ringer for opens, and a-k for a kick.keep us posted will help all we can.

Thanks, Ed and Jim.

I will test for opens and shorts in the coil. And jumper slate to slate/red too and see if I drop dialtone. I will open up the net box and eyeball the cap. I don't have a cap tester here but may just replace it (them) on general principle.

As to the REN 5 issue, I have reduced the jacks in my house to one. Straight from the NID via CAT 5 cable to the jack. I did this to get the telco to address a DSL issue long ago and haven't needed or wanted other jacks since. In testing the phone, I removed the DSL filter/splitter combo and plugged straight in. Tomorrow I may plug the phone into the line at the NID and bypass my home wiring alltogether if the other tests don't yield anything useful. Like many people, I use a cell phone a lot but want a good land line when I need it. I am sick of the cordless batteries and static even on the good AT&T 5GHz. I have a corded phone too but it's so light that it slides on my desk every time I pick up the receiver...hate it...

Thanks again!

I'm sorry I didn't answer your question about ring voltage. I know it's supposed to be 90 volts at 30Hz but didn't test it.

Also, thanks for figuring out that I meant the bias spring. I'm learning!

The ringer should respond fine to 75-105 VAC at 20-30Hz with no problem.

The ringer should respond fine to 75-105 VAC at 20-30Hz with no problem. If you really want to go to the trouble, you should read continuity from the black coil lead to the slate and from the red lead to the slate-red. I'm pretty sure that your problem is the capacitor.

I don't think you can open the "net box" without screwing up the network. As an after thought; look real close at the clapper near the end where the magnet is; there may be metal filings in there, use a piece of electrial tape bent double to get them out.

The 2500 DM will probably have a C4A ringer, or equivalent. I have several hundred in a junk pile here. If you will send me your contact info, I'll give you one (or two, or three).

Update:

The coils in the transformer are open. There is infinite resistance between all terminals on the transformer. There are no markings on the transformer either so I don't know what to replace it with either.

The net is difficult to open and is full of goo. It's been forever since I've seen electronics sealed up with those bent tabs on the top. I will drill the rivits holding it onto the base and open it up to see what is in there and replace the cap(s).

Jim, I used compressed air to blow out the base when I first opened it for the dust but didn't see any filings or swarth.

Arthur, you're too kind. Let me fiddle with this a bit and see if I can make what I have work. As for the coils in the transformer, does anyone know the part number or specs? I can see it is obviously a two winding transformer with iron core (yeah those little things fell out like feeler gauges!) but I have no idea about the step.

Thanks again!