In order to hard reset a Cricket A100, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Cricket A100 device will be brought back to the default configuration of a brand new device.
1. Turn on the phone. Dial *228.
2. Now type ##4357*
3. Scroll to the bottom and select Reset. If needed, type in the code (000000 by default).
4. Now dial *228 again and press Send. Phone will now reset and restart. Voila.