Since you haven't used the TT4 in quite some time, I suggest reprogramming the firmware.
This will ensire it is up to date.
After that I would do a "RESTORE" to get it back to factory.
Then go through and configure the needed parameters.
If you only get the ? and no "Press ESC 3 times to enter TT4 Options Menu", then you will definitely want to reload the firmware.
Be sure you match ed the version with your chip!
Interfacing with HTs can be very tricky with any TNC.?
There are several aspects to consider:
?? PTT - several HTs tie the PTT to the audio in and require the TT4 jumper to activate.
???????????? Does the TX LED on the HT come on and no audio, or no TX LED?
???????????? If the TT4 TX LED comes on but HT TX LED does not place jumper on JP8 and try again.
? Audio - Because the HT mic is built into the device, the sensativity can be much more difficult to set.
????????????? Typically the TT4 levels need to be very low, so once you get PTT working you can adjust the audio output.
The jumper for JP6 has to do with power to the GPS or 5V in to power the TT4 (typically when programming).
As for LEDs should flash in sequence, then reverse.?
After that, they should provide status.?
If only the GPS and CD are ON, I think it is in program mode for the firmware - from memory, not sure.
? Again first comment fits - reload firmware.
