Seite 1 von 1

TW-39 board problem

Verfasst: So 8. Dez 2019, 17:49
von kphill01
Greetings. I finally got active on i-Telex a week or two ago. I have the "special" power supply board, the i-Telex board with one serial connector, and the TW-39 board. I was using the "reverse" connection system. My machine is a Western Union Model 32ASR. I replaced some resistors in the call unit so it would work with the i-Telex system. It was working well until late yesterday (Saturday) afternoon. I noticed I stopped receiving incoming messages. I could still dial out to send message but people attempting to send messages to me were receiving "NC" or "BK" returns. I could dial the weather server and receive weather reports. I dialed into the power supply and printed the bias and distortion tests. On the Web administration interface it seemed to change spontaneously from "reverse" to "normal" system. I tried switching back and forth between the systems but could not receive messages. I was receiving an internal message saying that my PIN to log into the subscriber directory was wrong and I should contact a server administrator. I tried generating a new PIN on the subscriber directory page but never received the printout on the machine. At times I noticed, when there appeared to be a message coming in, that my machine would run "open" for a time and then stop. I tried dialing into the power supply for the distortion tests but the machine would run open. I tried resetting the i-Telex board. The board appeared to go through the re-set process but nothing changed. I tried removing power from the boards and re-powering. The yellow light on the TW-39 board would light constantly and then after several seconds the red light would light and remain on. This morning I tried measuring the voltage on the loop connections on the back of the board. At first I measured 95vDC but no current. After a few minutes I measured again and measured 0vDC and 0mA. I pressed the button on the front of the board and held it down. A few times the green light would flicker and the machine would print a few characters but most of the time it would run "open" and the red and yellow lights would be lit. Presently, I am not able to dial into the power supply at all or dial out. I would appreciate any suggestions on how to troubleshoot the problem

Thank you,

Kevin

W5TTY

Re: TW-39 board problem

Verfasst: So 8. Dez 2019, 18:06
von Franz
Hallo, falls Übersetzung gewünscht ist, kann man den Text in "deepl.com" kopieren und der übersetzt das relativ gut in's Deutsche :thumbsup:
Hello, if translation is desired, you can copy the text into "deepl.com" and it translates it relatively well into German. :thumbsup:

Re: TW-39 board problem

Verfasst: Mo 9. Dez 2019, 07:54
von FredSonnenrein
Hi Kevin,

At first: Please insert some paragraph breaks next time. It's quite hard to read.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 Greetings. I finally got active on i-Telex a week or two ago. I have the "special" power supply board, the i-Telex board with one serial connector, and the TW-39 board. I was using the "reverse" connection system. My machine is a Western Union Model 32ASR. I replaced some resistors in the call unit so it would work with the i-Telex system. It was working well until late yesterday (Saturday) afternoon. I noticed I stopped receiving incoming messages. I could still dial out to send message but people attempting to send messages to me were receiving "NC" or "BK" returns. I could dial the weather server and receive weather reports. I dialed into the power supply and printed the bias and distortion tests.
That far, everything sounds good.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 On the Web administration interface it seemed to change spontaneously from "reverse" to "normal" system.
I don't understand what you mean with "normal" and "reverse" system. Plase explain.
ADDITION: Henning explained, that you mention the "remote server option". Yes, this option is automatically cleared, if the wrong PIN is used.
Just switch it on again. Be sure to leave the "PIN for sign in at subscriber directory server" unchanged as long as it's not zero. If you want / need to change it,
just contact me or henning.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 I tried switching back and forth between the systems but could not receive messages. I was receiving an internal message saying that my PIN to log into the subscriber directory was wrong and I should contact a server administrator.
In this situation you should have called henning or me.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 I tried generating a new PIN on the subscriber directory page but never received the printout on the machine.
That PIN is only valid for the "news"-server but not for the subscriber directory server. Yes i know, there is a link on the web page of the subscriber server to the news-server. I will delete this link to avoid this confusion next time...
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 At times I noticed, when there appeared to be a message coming in, that my machine would run "open" for a time and then stop. I tried dialing into the power supply for the distortion tests but the machine would run open.
It seems that something of your call unit got damaged.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 I tried resetting the i-Telex board.
The "i-telex-Board" (you should better call it ethernet interface board) is completely uninvolved when you dial the test generators of the power supply board.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 The board appeared to go through the re-set process but nothing changed.
Yes, as mentioned above. The ethernet board only acts as an <<translator>> between the internal connections and the ethernet.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 I tried removing power from the boards and re-powering. The yellow light on the TW-39 board would light constantly and then after several seconds the red light would light and remain on.
This indicated without any doubt that the call unit is in the "call" state, as if you have pressed the call button. This is shown by the yellow LED. The red LED indicates that no dialing pulses have been received 45 seconds after "call" begin. BTW: Do you have a rotary dial or do you use the "keyboard dialing" feature?
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 This morning I tried measuring the voltage on the loop connections on the back of the board. At first I measured 95vDC but no current.
Absolutely no current or something aound 3 mA? The 'standard' TW39 call units normally draw 3 mA in idle state, but your unit may be different.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 After a few minutes I measured again and measured 0vDC and 0mA.
Strange. Please check the state of the green LED of the power supply board. All 4 LED constantly on?
Can you measure the voltage at the backplane lines 26 and 30? (the fourth and the second connector pins counten from bottom). The shall be a voltage of 60 to 80 V all time.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 I pressed the button on the front of the board and held it down. A few times the green light would flicker and the machine would print a few characters but most of the time it would run "open" and the red and yellow lights would be lit.
All your observations indicate a problem either with the loop voltage supply, the TW39 board or the call unit.
kphill01 hat geschrieben: So 8. Dez 2019, 17:49 Presently, I am not able to dial into the power supply at all or dial out. I would appreciate any suggestions on how to troubleshoot the problem
If you have a double port TW39 interface card, try to use the other "half" of that board. If your problem persists, we can disclose the TW39 board from the list of possible wrongdoers.

Best regards,

Fred

Re: TW-39 board problem

Verfasst: Di 10. Dez 2019, 03:06
von kphill01
Hi, Fred Thank you for your reply.

I have a rotary dial unit (Model 32ASR real machine)

All four lights on the power supply are constantly green.

I am not sure which connectors are 26 and 30. They do not have numbers that high. Measuring at the second and fourth connector pins from the bottom I find very little or no voltage; about 0,35v at most.

The call unit in the machine does have a problem which has just happened. It may be a large capacitor. I replaced the capacitor about a year ago. I have ordered another capacitor and will try to replace it tomorrow evening (Tuesday). I will report more when I have replaced the capacitor.

Thanks again,

Kevin

Re: TW-39 board problem

Verfasst: Di 10. Dez 2019, 08:10
von FredSonnenrein
Hi Kevin,
kphill01 hat geschrieben: Di 10. Dez 2019, 03:06 I have a rotary dial unit (Model 32ASR real machine)
Okay
kphill01 hat geschrieben: Di 10. Dez 2019, 03:06 All four lights on the power supply are constantly green.
Good
kphill01 hat geschrieben: Di 10. Dez 2019, 03:06 I am not sure which connectors are 26 and 30. They do not have numbers that high. Measuring at the second and fourth connector pins from the bottom I find very little or no voltage; about 0,35v at most.
I'm not able to take a photo currently. I meant the soldered connector pins of the long grey colored PCB connector.
In other words the small solder pins directly BELOW the printed labels "C24" and "C20".

Explanation about the numbering: C20 and C24 and the other labels are generally related to the blue colored screwed connectors directly RIGHT of the corresponding label.
The grey plug connector have pin numbers A2 to A32 and C2 to C32 (only the even numbers are used).
As viewed from the back side the column A is on the right hand side and C is left, 2 at top.
The pins A2 to A12, A26 to A32 and same with C are only internal connections between the boards (bus), so they are
neither labeled nor connected to the blue screwed connectors.
kphill01 hat geschrieben: Di 10. Dez 2019, 03:06 The call unit in the machine does have a problem which has just happened. It may be a large capacitor. I replaced the capacitor about a year ago. I have ordered another capacitor and will try to replace it tomorrow evening (Tuesday). I will report more when I have replaced the capacitor.
Goos luck!

Fred

Re: TW-39 board problem

Verfasst: Di 10. Dez 2019, 09:42
von DF3OE
Thanks to a guy from the Greenkeys mailing list here is a link to the manual of the model 32 control unit:

http://navy-radio.com/manuals/tty/jh/bs ... -101TC.pdf
http://navy-radio.com/manuals/tty/wd/7083wd.pdf (full schematic)

Re: TW-39 board problem

Verfasst: Mo 16. Dez 2019, 14:20
von DF3OE
Here is another Scan of the control unit schematic (Thanks to Chuck N7UVZ), now directly on the telexforum.de server:
WD 6360-1.pdf
Hopefully it might help to solve the problem.

Re: TW-39 board problem

Verfasst: Di 17. Dez 2019, 09:04
von FredSonnenrein
I tried to understand the basic principles of the control unit.
But there are some "unexpected" symbols: The buttons "START", "LOCAL", "STOP", "DIAL" at the top edge of the drawing.
The start button at the top left edge is a simple "bar" across the connection, while the local button is an "X".
Can somebody explain those symbols? i expect thar they are simple "normal open" or "normal closed" contacts, but i'm not sure...

Re: TW-39 board problem

Verfasst: Di 17. Dez 2019, 10:44
von ProgBernie
I think the bar is a NC, the cross a NO contact. That makes sense in this circuit, otherwise the buzzer would be always on (both relays K2 and K3 will be in the off state, otherwise the bulbs LOCAL or CONN would be illuminated in idle state) Note that the push buttons have several levels, as START S1 and STOP S3 appear more than once in the diagram.