atcomsystems.ca/forum Forums General General Telephone & Systems Information Old Speakerphone #108: Need Help

My father uses an AT&T Conference Loudspeaker Set #108 connected to a single-line Western Electric 2500 SM pushbutton desk phone as his home phone. The speakerphone has worked fine for decades until a couple weeks ago when the loudspeaker stopped playing or receiving a dial tone. He does not know if it is a problem with the rocker switch that turns the loudspeaker on-off or a problem with the speaker. He lives in small town in the Texas panhandle and has not found anyone who can help. Any recommendations for a repair service where he can ship the equipment would be appreciated.

You probably won't find anyone who can repair this (he has a 4A speakerphone system, by the way). I'd be willing to bet that the power transformer that plugs into an AC outlet is either unplugged or one of the wires connecting to it have broken loose from the screw terminals. Those things are fairly bulletproof otherwise.

If it is getting power, you'll hear a click from inside the 108A speaker when the toggle switch is turned to the on position. If not, I'll bet it is a power problem. If the transformer is bad, they are an easy replacement.

Thanks, Ed, for the quick reply. We'll try those suggestions. If we can't resolve I may be back with more questions.

the top of the on-off switch pops right off, and you can clean the base and the contacts (only 2) with an eraser; adjust the contacts by bending them gently toward the base and snap it back on see if that helps.

I really appreciate the suggestions and have passed them on to my father.

Can you tell me more about obtaining a replacement transformer if it comes down to that? Is it a common model?

I have plenty of them available for sale. Let's make sure that is what the problem is before we resort to that. My money is on a broken wire connecting to the transformer, the #1 cause for failure on these systems.

My father is not having any luck figuring out the cause of the problem and is waiting for me to visit in a few weeks. So it will be several days before I know whether I need to get a transformer from you. Thanks again for all of the help.

I've recently had a problem with my 4A speakerphone as well. A few years ago up until the present, I would either answer or make a call and after about 4 minutes, the loudspeaker would just turn off suddenly. Then, I would try again, but it would suddenly turn off again but even sooner. Each time I would try again, the sorter the time until it would click off until I couldn't even get a dial tone. If I waited about a half hour, it would work for a while, then turn off in the same shorter pattern.

The unit came with a different power transformer unit than the 85B1 Power unit Its "Precision Components Telephone, INPUT 115V AC 60HZ, OUTPUT: 16V AC 375 mA, MODEL: 0501-0372 PC-2012HD-3

I hope this is enough info (If necessary, I'll list all the components).

I'm really hoping I can get this beautiful technical marvel to work as it should. Many thanks for your help so far (about the led lamp in the other forum, Ed)
Rusty

l'Acadie: The fading speaker might be due to the touchtone dial common switch contacts being dirty.

Look at the back of the TT dial. There is a clear plastic cover that snaps off. Take it off, and you will see a bunch of MAKE (normally open) and BREAK (normally closed) contacts that all move in COMMON when any TT button is pressed.

These contacts do several things, but the ones you are concerned about are the speaker muting contacts that reduce the sound level coming from the speaker (and the receiver unit in the handset) whenever you press a TT button.

Take a business card or a small piece of good quality bond paper, and put it between the contact pairs, one pair at a time. If the contacts are make contacts, put the paper between them, press a TT button, while gently sliding the paper back and forth. Then release the button.

If the contacts are break contacts, press a TT button, then put the paper in between them, then release the TT button, and slide the paper. This sliding will clean the contacts. DO NOT USE ANY OTHER CLEANING OR BURNISHING METHOD, regardless of advice from others. The contact springs have gold or gold alloy contacts that can be damaged easily.

If the dial proves to be the culprit, and it works properly, that's the fix. If the dial trouble recurs, you can replace the dial with another WE TT 35-type dial, but it must be one from a key telephone like a 2565HK, not a standard 2500-D, because you need the extra contacts (and associated leads) that only are found on a special dial that is used in key sets and the 2500-S...phones that are specifically designed to accommodate speakerphone service.

Rusty:

When the outage occurs, do this: Without pressing any buttons, or changing any settings, take a VOM and see if you are getting 18 Vac from the transformer. If the transformer is dodgy, replace it. It may be some other problem with the major components, (speaker/amplifier/control unit, or transmitter unit,) in which case you need to tell us which one, so we can replace it for you.