It will help us help you with answers to Mark's questions above.
A yellow flashing light on a Jaguar indicates it has power but no control signal. (
More info here, pick the black jaguar getting started guide)
One possible cause for no control signal is missing or mis-wired PWM signals. The photos seem to show correct wiring, and you asserted that before.
Did you "enable" the robot from the driver's station? I'm not that familiar with it, but I remember there's a big red button on the display screen that needs to be green. A disabled robot cannot produce PWM signals.