How do I Reset My Vantage Lite?
Your VTL is locked up and you cannot use it: Try doing these Resets first.
Reset Options:
Note: You will loose any un-saved work programmed between now and the last time the device was turned off, by performing these resets. If the unit allows, turn the device off then back on before trying these resets.
Option 1—ON/OFF Button: 
Press and hold the ON/OFF button on the front of the case for about 10-15 seconds until you see a white screen, then release it. If your device is still not responding see Option 2.
Option 2—Reset Button Option
Insert the end of a straightened paper clip or toothpick into the small hole on the bottom right corner on the back of your device. Push gently when the paper clip encounters the reset button. Remove the paper clip. Your device will reset.
Option 3 - Battery and Card Reseat
If you see the Vantage LOGO on your screen and the device will not boot up beyond that, then most often the device is no longer recognizing the software card in the back. Remove the large battery door on the back of the device and unplug the battery pack. Remove the battery pack and you will see the software card seated in the lower right side of this compartment.
Pull on the piece of tape attached to the card to remove the card, then re-install the card the same direction it came out. Press firmly on the card, making sure it is in tightly. Replace the battery pack connector and battery door.
If this does not fix the problem:
Call the PRC Service Department at 800-262-1990 for further instructions.