In order to change the batteries of your AlphaSmart Pro, you must first open the battery cover that is located on the rear panel of the device. Next, remove the batteries that are already in the device. Lastly, insert two AA batteries of the same type into the cavity, making sure that the positive (+) and negative (-) ends are located in the proper terminals. If you have further questions, please see this guide for a step-by-step solution with pictures! (Link is coming soon!)
You may need to check your batteries. First, plug your AC adapter into your AlphaSmart Pro. If the device turns on, your batteries must be discharged or have been improperly inserted. Make sure the batteries are oriented as indicated in the battery cavity.