atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telephone Repairs & Equipment Troubleshooting 1970s-era AE "Desk compact"

I have a 1970s-era AE "desk compact" (i.e., "keypad Starlite without the night light"). It was my rental phone (by the time I finally bought it out, as I recall, the buy-out price had dropped to about the same as a month's rent).

Twice, in the past few months, it has gone dead on me, while all other phones on the same line were fine. The first time, opened it up and cleaned all the contacts, and re-torqued most of the terminal screws, and at some point, it began working again. This time, I only got as far as opening up the handset before it started working again.

As a programmer, I know full well that the hardest thing in the world to diagnose is an intermittent problem. But can anybody point me at what to look for?

One other thing, that might be connected: when it does work (which is most of the time), it frequently sounds "staticy" for the first few seconds after being picked up.

Given that this has outlasted every other phone in the house a dozen times over, it's not something I'd care to throw out.

Back in the day, we used to firmly smack a carbon mic handset on the desktop to shake up the carbon in order get it to work again.

Oddly enough, I have amazed a few of my younger co-workers in recent days when having 'fixed' a non-working electronic handset by the same method.

Now I don't suggest you beat on this wonderful old phone, but you never know...

I would look at the hookswitch

(Beating the transmitter isn't going to affect the receiver function )

When it acted up the first time, the hookswitch (yeef! that thing has a lot of contacts!) was the thing I spent the most time cleaning.

Anything else I should try doing to it, besides cleaning? Or any particular set of contacts I should examine more closely?

Incidentally, when it acted up last night, I have confirmation that I could not only not hear anything, but could not transmit anything, either.

The one thing I'm kicking myself for *not* doing: even though there's another phone, normally on my fax/modem line, that I could have plugged in (to see whether the problem was in the wall), I didn't. (But I vaguely recall trying that the first time, and I suppose I wasn't thinking all that clearly last night, given that I'd picked up some sort of bug that had me in bed with a 100-degree fever).

Thanks to both of you for responding so quickly.

Might just be contacts on the dial pad

When it is "dead", does it draw dial tone and you just can't hear it through the earpiece, or does it not even connect to the line?

What exactly did you do do to clean the hookswitch contacts?

Some type of spray, or a contact burnishing tool?

Perhaps it still needs attention.

Also, on the touch tone pad, there is a set of contacts on the back that move every time a button is pressed. One set interrupts the receiver element, so you don't blow out your ear with super loud tones. If they don't make good contact when you release the button, you won't be able to hear.

If the network is not the "potted" type, but a printed circuit board instead, there may be a broken trace caused by dropping the phone.

If you have never adjusted contacts this may be the issue.

You should use a burnisher tool along with duckbill
pliers.

Focus on hookswitch and dial contacts.
Could be either.

Do not use cleaners on contacts unless you know
the end results, as you will probably make it worse.

Thanks again for the continued responses.

Still haven't opened it back up, but had another malfunction today: it rang, and I picked it up. Completely dead. Left it off-hook, and ran into another room to pick up another phone on the same line. By that time, the calling party had disconnected. When I returned, I had dial tone in the problem phone.

That almost sounds like something's being slowed mechanically -- like some sort of viscous dampening -- and delaying the hookswitch contacts from making. That might also explain the static: if something is becoming mechanically sluggish, then the "initial static that eventually clears up" might be from the mechanical problem causing a "loose" make, that improves over time, and the "intermittent dead that goes away by the time I try to do anything about it" might be from the mechanical problem delaying the make completely.

Does any of that sound at all sensible? Or am I sucking antimatter?

To Touch Tone Tommy: How would I tell if it's drawing dialtone, but not audibly? And as to cleaning the contacts, the first thing I tried was 91% isopropanol, mostly applied to various kinds of paper and pulled between the contacts. I think I used to have a contact burnisher of some sort, but I have no idea where it went, or even if it's the right kind (and would not want to use anything too coarse!)

still sounds like hookswitch , you lifted the handset but no contact was made so the phone continued to ring

Hookswitch contacts are either dirty or out of adjustment.

James-

Today, when the phone rang, and you picked up the handset, did it continue to ring? Or did it stop while you ran to the other phone?

If the ringing stopped, but you didn't hear the calling party, your problem can be described as "Can't hear".

If the ringing continued, you "can't draw dial tone"

Sorry to go so long without responding, but I had to wait for the malfunction to return!

This evening, just on a wild hunch, I checked to see if it was back, and got lucky.

So I called myself from my fax/modem line (after making sure nobody else picked up the call), with the following results:

Ringing stopped when I picked it up (which was as before, actually).

I could transmit (at least this time), but could not hear.

I then swapped phones between my main line and my fax/modem line. Definitely the phone, not the line.

Violent shaking of the base had no effect.

Unscrewing the mic housing on the handset got me dialtone, the very moment the cartridge came loose (yet I'm sure I successfully talked to the other line -- how could the mic be pulling it down and still transmit successfully?)

Ringing stopped when I picked it up (which was as before, actually).

So it's not the hookswitch, unless the Brown and Green contacts are not opening (they short out the receiver when the handset in on the cradle)

It's connecting to the line, but the receiver is dead. You could have a bad handset cord. Unfortunatly, it's a 4 conductor, and there is no common on the AE's. You could try changing it out, using any 4 conductor cord, even if it's not a coiled one of the correct color, at least to test it.

You can find schematics for the Starlight with the newer touch pad and older touch pad

Given that the problem seems to occur only when the phone is left undisturbed for long periods of time, I left it a good two weeks.

I picked up the handset about a minute ago, very carefully causing as little disturbance to the handset cord as possible. Again, dead receiver. Holding the receiver to my ear, and taking care not to disturb the handset cord in any way, I carefully unscrewed the mic housing.

As it began to come loose, I heard a faint crackle in the receiver, then it came to life with ringback (either the dialtone had timed out, or the unscrewing of the mic housing had pulse-dialed somebody; not exactly wanting to find out which, I grabbed the hookswitch).

So that brings up two questions:

1. How could the mic cartridge drag down the receiver?

2. Where would I find a replacement carbon mic cartridge? The markings on this read:

D-38379-A
GTE 810
2
OX (or XO?)

Picking up the cartridge by itself, and shaking it by my ear, I can hear the carbon rattling around, rather like fine sand in some small percussion instrument.

I'll look in the dreaded basement and see what I can find. I may have one of those.

Also - The transmitter and receiver are wired together. Anything is possible. Have you tried changing the cord yet?

Sam

Somehow, I get the feeling that finding a new hardwired handset cord (much less one in light blue) would be as big of a challenge as finding an exact replacement mic cartridge.

I've seen other mic cartridges available from various sources, but they don't look quite the same. Assuming they're made to fit WE, rather than AE handsets, would they have the right impedance, and the right physical dimensions?

Another thought (after looking at the schematics supplied by Touch Tone Tommy):

The "WA-1155 transmission unit" (I just looked, and that's the version I have; it says "WA1155A" right above an 82-Ohm resistor): Is there anything that could go wrong with it, that would only show up after the phone sits unused for several days (and/or from ringing), that would reset itself if the mic was momentarily disconnected while it was off-hook?

And Skip: Thanks for the referral to "Phoneco"; they apparently not only have exact replacements for both the mic and the handset cord, but may even have the cord in light blue (I'm waiting for an email on that detail), to match the body and handset.

It got cranky again.

This time, while it was acting up, I grabbed the cordless that's on the same line. I still don't know whether it actually "draws" a dialtone, but I do now know that it can transmit when it's acting up.

I also tried an ohmmeter across the receiver, while it was acting up. It registered finite resistance, and the receiver clicked when applying or removing the ohmmeter.

The receiver is across the black and yellow wires in the handset cord. They both check out as zero ohms.

Unfortunately, as usual, opening the phone up seems to cure the problem.

Can somebody explain the hookswitch contacts on this model?

Do you have a part number to this phone, as in 182 or 182A? It's the "compact" phone with the dial between the place where the handset sits and the base (when you separate the phone top and bottom) has a mini-ringer?

I have prints for all AE phones in my station user's manual from 1976 or so and earlier.

Carl