Re: TMD700 "Opening TNC"



This process is spelled out in a PDF document in a folder (the second one [with my call, K9DCI] on it) in the Files Area. I included some of the other solutions I found.  I'm pretty sure I did not have this hardware solution described by Pete, but should add it.


I also wrote macros in an Excel spread workbook that will semi-automaticlly SEND  the steps out a serial port or USB port with a USB-Serial adapter.  If anyone wants it contact me.  I should upload it as well.


73, Steve, K9DCI



---In TMD700A@..., <davidf4@...> wrote :

Here’s a terminal based reset from my archives


-----Original Message-----

From: Dennis Hudson [mailto:n2lbt@...]

Sent: Sunday, June 08, 2003 6:27 AM

To: TMD700A@...

Subject: Re: [TMD700A] "Opening TNC" Fix without reset



I can confirm that the problem is GPS communication related. I recently 

switched from a moded Tripmate to a Motorola Nextel i88 for my gps. The 

phone GPS stream can do weird stuff while it is in the cradle while the 

D700 is in APRS mode. Once a week it will hang the D700 into the 

"Opening TNC" routine. I will have to try resetting the TNC via the 

serial port, but in the mean time I'll just reset the PM which doesn't 

nearly piss me off as much as doing the hard reset.


Dennis, N2LBT



On Saturday, Jun 7, 2003, at 23:31 America/New_York, Randy Mclean wrote:


> Here is a simple fix for the "Opening TNC" hang up without doing a

> reset. I tracked the problem down to the GPS feature. I found I could

> duplicate the problem if it was on and you break the computer serial

> connection while its sending gps data. You will lock up the next time

> you switch back to APRS mode.  You can send the following commands in

> a terminal session to unlock it.



> Open Hyperterm at 9600,8,1,n

> type "TC 1" this means Terminal control on

> Now type "GU 0" This turns the GPS option off

> Now type "TNC 2" this puts the radio in "PKT" or packet mode

> Wait until "Opening TNC" goes away

> Now type "TNC 1" this puts the radio back in APRS mode

> Wait until "Opening TNC" Goes away

> Now type "GU 1" or "GU 2" 1 is 4800 NEMA while 2 is 9600 NEMA

> Finally type "TC 0" to take the radio out of terminal control





From: TMD700A@... [mailto:TMD700A@...]
Sent: Saturday, June 14, 2014 6:36 AM
To: TMD700A@...
Subject: RE: [TMD700A] TMD700 "Opening TNC"


I know this is an old thread but no one seemed to find a solution.  I had this happen this week on my D700 and tried everything suggested (terminal commands, hard reset, soft reset, all sorts of resets) with it still sticking Opening TNC when trying to go into TNC mode which is first APRS mode.  I did find a solution that got my D700 back working normally but it takes the ability to take both covers off, slide the front bezel off, and reset the TNC manually.


Unplug all cables from the D700.

Remove top and bottom covers and then remove the front bezel (bezel is held on by 3 tabs on the top and 3 tabs on the bottom that latch over the main chassis).

On top under where the back of the bezel used to be is a small circuit board with a flat cable coming out of the top left (as you look at it from the front) that connects it to the main circuit board.  Your goal is to disconnect the cable and reconnect it without breaking the connector or the cable.  This fully resets the TNC and will allow it to work normally.

To remove a flat cable from a circuit board, you have to release it from the connector.  The connector for flat cables is 2 pieces, one that is fixed to the circuit board and a second which is on top of the flat cable and faces the flat cable.  GENTLY use a small screw driver to evenly push this second piece away from the fixed piece of the connector.  It is NOT removable, only push it out far enough to be able to EASILY pull the cable out from the connector.  Once you have fully disengaged the cable, push it full back into place followed by gently pushing the top of the connector back in place.  Once it is secure, put the bezel back on followed by the top and bottom, re-cable, and power on.  You will have to reset the time and date as that was lost with the TNC hard reset.


Hope this helps you save some money in needless repair costs!  I definitely recommend this only if the other solutions don't work as you can potentially break the connector, cable, etc. if you are not gentle.




Pete AE5PL

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