Looks to me you have the Jaguar wired backwards - the wires from the PD board with yellow tape should go to the left side - marked with a V+. the right side is marked with a M+ is the output to go to the motors.
see:
http://content.vexrobotics.com/docs/...e_20130215.pdf
As Al said they are not protected from being wired in reverse so the Jaguars may be dead now.