Solution 11185: TI Connectivity Cable Drains Power From TI Graphing Calculators.
Can the TI Connectivity cable drain power from a TI graphing calculator?
If the TI Connectivity cable is plugged into the TI graphing calculator and computer but the TI Connect software is not running, the cable will also drain power from the unit.
The TI Connectivity cable gets power through the DTR line of the serial port. However, it is normally off and the TI Connect software turns it on. The cable should therefore be plugged into the TI graphing calculator after it is attached to the computer while the TI Connect software is running.