Hi Jordan,
From your description, it looks like still the power issue.
What’s kind of the batteries do you use. If the power from battery is very low, the motor won’t rotate even connected with USB cable. You can change the suggested rechargeable battery have a try.
Besides, is this the first time you use the Ranger robot, please make sure the robot has the factory default program. You can also reset default program for the Ranger with mBlock software.