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AE 186 W Dial on the fritz

Started by Partyline4, September 01, 2015, 10:34:56 AM

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Partyline4

To make a long story short,

I hooked up the the 186w and noticed a constant tone over the line - stuck key in the dial

I take the dial apart to clean it, and put it back together

Everything works except the 2,5,8, and 0 keys.

I had put the connections back wrong on the little fork piece pictured.



I then compared them to my other 186 that works.

I made the appropriate corrections, but now the dial doesn't do anything!

I was hoping someone may know of something quick before I take this thing apart to see if something is unplugged or fried.

Thanks in advance!

Partyline4

#1
So I've determined that nothing is unplugged ( took a good look all around the innards ). What a mess of wires in that thing!  :o

I've also determined that it has to be something either not making a contact because of a mechanical fault, or an electrical fault (short).

At the moment, when a button is pressed, a small pop is heard and the line goes quiet. This was very similar to the polarity protected W.E's I piddle with. I changed the polarity on the A.E to no avail. There is still something wrong.

I've learned that the little contact switch like I have pictured definitely leads to my point of failure. With the switch completely removed, there is no noise at all when a key is pressed.

I have it back in, making and breaking like my other 186, but I still get no tones.....

Something electrical...but what?

I might try taking the dial apart again later...

All of the diagrams on TCI are for the rotary version......


don't be afraid to chime in, guys.

Partyline4

Took the dial apart and put it back together again.

I realized that sometimes when you take these dial apart the little contacts space around the perimeter of the dial tend to get pushed and pulled - distorting them.

Something is still not making contact.......

I can't wait to figure this one out.   ::)

andre_janew

All I can tell you is to use the working dial to figure out how the contacts should go.  If misaligned contacts are the problem, getting them straight should fix it.

Partyline4

Just discovered a possible problem.

The transistor on the board is missing a connection....

Possibly a burnt leg when it shorted out somewhere?

I'll go fix it and see if that's it.


Phonesrfun

On a TT dial, there is one transistor that makes dual tones for all tones.  If everything works for all buttons except the vertical row 2,5,8 and 0, then the transistor is working and the problem is either the vertical contact switch for that vertical column of numbers or it is an open coil tap on the coil for the center vertical column.
-Bill G

Partyline4

Got her working again! The transistor had come unsoldered during rough handling.

All is well.

Jack Ryan

#7
Quote from: Phonesrfun on September 01, 2015, 07:29:51 PM
On a TT dial, there is one transistor that makes dual tones for all tones.

The usual progression for TT dials is:
1. LC oscillator & 1 transistor
2. LC oscillator & 2 transistors
3. IC oscillators

There are also variations where the designers didn't use bridge rectifiers to compensate for reversed polarity.

Both WE and AE used 1 and 2 transistor designs.

See: AE 997-306-500.i4 DTMF DIALS (Touch Calling) in the tci library

Jack

Jack Ryan

Quote from: Partyline4 on September 01, 2015, 07:50:30 PM
Got her working again! The transistor had come unsoldered during rough handling.

All is well.

Well done!

When I heard the words "short circuit" and "burn" I thought it was a gonner.

Jack

Phonesrfun

Quote from: Jack Ryan on September 01, 2015, 07:56:07 PM
Quote from: Phonesrfun on September 01, 2015, 07:29:51 PM
On a TT dial, there is one transistor that makes dual tones for all tones.

The usual progression for TT dials is:
1. LC oscillator & 1 transistor
2. LC oscillator & 2 transistors
3. IC oscillators

There are also variations where the designers didn't use bridge rectifiers to compensate for reversed polarity.

Both WE and AE used 1 and 2 transistor designs.

See: AE 997-306-500.i4 DTMF DIALS (Touch Calling) in the tci library

Jack


I can't argue with success, but it seems odd that even with two transistors that the second transistor would be only functional for the center column.  I had forgotten about the two-transistor model.
-Bill G

Jack Ryan

Quote from: Phonesrfun on September 01, 2015, 08:41:36 PM
I can't argue with success, but it seems odd that even with two transistors that the second transistor would be only functional for the center column.  I had forgotten about the two-transistor model.

Bill,

I was just commenting on the circuit design. Generally one transistor was used for the high tone oscillator and the other for the low tone oscillator.

Jack

Partyline4

Here's a pic of her resting place for the moment.



Both phones have ringers in them, but I want to leave them silent.

Thanks for your information, guys!