Blinking Jags aren't related to the joysticks, so don't let that distract you.
First step is to get the Jag lights to go solid, meaning they are communicating with the DSC and cRIO and the cRIO is Enabled.
It'll be either electrical or programming.
Using a simple 4 motor drive should reduce the possibility that it's the code.
Just make sure the PWMs match up to the Jag connections. The only code problem that causes the Jags to blink is Disabled or failure to Open the corresponding PWM output.
Electrical checks
- Communication: DS Communication & Robot Code lights green and robot Enabled.
- Power: Digital Sidecar status lights all on strongly, cRIO status light green
- DSC Connectivity: RSL long on/short off blink for Teleop. Check the 37-pin cable connections at both ends for bent pins. Check the cRIO Digital Module connector to the cRIO chassis for bent pins or metal dust/shards. You can try the alternate slot 6 to see if the module connection has a problem (have to update the code though).
- Jag Connectivity: check the pwm connections for correct polarity. Check to see they are seated correctly. With 4 of them I doubt you have 4 bad PWM cables.
Vaccuming is good. Do it with the DSC too.