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.