The TI Nspire has a hierarchy of power consumption. Assuming that there is an external power source, then the hierarchy is wall power ==> internal rechargeable battery ==> lab cradle. What it looks like for your problem is that the battery is bad or the connection is faulty. On the back of the calculator, beneath the reset button, there are two Phillips head screws. Remove these two. DO NOT REMOVE THE TORX SCREWS!!! This will easily void your warranty because there is a tamper-evident ribbon. The battery is underneath the compartment with the Phillips head screws. Push in the white battery connector and try again. If there is any visible battery damage, do not continue using the calculator. If the battery is more than three years old, then there is a chance that the battery has reached the end of its life cycle. The battery is only covered under the warranty for one year. (If your battery explodes within one year, they'll send you a new one, otherwise, good luck.) Batteries are available for purchase at education.ti.com.