I pulled two cortex microcontrollers and two joysticks from our parts bins at random, verified each would power on, and then attempted to pair any two of them in all four possible combinations using a USB tether.
None of the attempts succeeded, and in each case, the VEX Robot Troubleshooting flowcharts led to the box with instructions to update the VEXnet firmware on both the Cortex and the Joystick.
Using VEXnet Upgrade utility V 4.1.7, I connected the devices and either verified “VEXnet is up to date. No action required.” (both joysticks were found up to date with Version 4.25), or performed an update to Version 4.25 (both Cortex microcontrollers required updates).
Using the pairing procedures, I connected tethers again and waited to observe respective VEXnet led lights turn solid green for more than 5 seconds, which never took place in any combinaton.
Next I selected one Cortex and one Joystaick, and for each, I depressed the CONFIG switch, and while holding the switch down, connected each device to the PC, releasing the switch after observing all LEDs solid Green. Both were updated using the VEXnet Utility to Version 4.25. Following updates, attempts to pair using a tether failed again.
For what it’s worth in case there is any significance to what was happening with the led lights:
On the Cortex I observe:
Robot- slow flash 5 sec, then off 3 sec, then single green flash, then repeat from the start
VEXnet - solid green 5 sec, then red flash 5 sec, then repeat from the start
Game - continuous rapid red flash
On the Joystick I observe:
All lights flash red about once every 10 sec, then in between these flashes:
Joystick - off 2.5 sec, then solid red 2.5 sec, then off 5 sec
Robot - off 5 sec, then 2 rapid red blinks each second
VEXnet - during the 10 sec intervals, 2 rapid yellow flashes just after all lights go out, and 2 rapid yellow flashes just before al lights come on again
Game - off between the 10 second interval flashes
Club members are usually more savvy about this stuff than I am, and they are also stuck. What else should we try?