Make sure no buttons are stuck. If not, then you can try the following three steps yourself.
First, power supply. Try an AC adapter that is a Celestron-recommended 12 volts DC, 2.5 amp output, tip positive source. For any external source, be sure the power port on the scope is clean and the pins in the center are slightly spread ensuring good contact with the car battery or AC adapter jack. Check the car battery adapter itself. Check AC extension cords and wall plugs.
Second, plug into an AUX port and try to reset to factory settings. Utilities > Factory Setting. This will put the hand control back to its default settings.
Third, reflash the hand control and motor control firmware. Download to your PC and install the HCUpdate and MCUpdate programs from celestrom.com/support. Using the RS232 cable and your PC, connect your scope through the hand control and run the update software either replacing your current versions of hand control and motor control firmware or upgrading to the latest versions.
If none of these work, most likely your mount and hand control need Celestron factory service to restore proper function.