There are a number of varying types of resets for Olevia TV's. The steps and types are dependent upon the model of Olevia TV you are trying to reset.
Most minor issues can be resolved in the OSD menu by navigating to the setup menu and activating either the FACTORY SETTINGS or FACTORY SETTINGS BY INPUT feature. These options are available on the Olevia 2, 3, 4, 5, 6, and 7 Series TV's. LT Series Olevia's are reset by activating DEFAULT in the SETUP menu.
If the reset you require is to correct a more serious issue, you may want to try an EEPROM reset. If you call Amergence Technology at 866-965-3842, their Level 2 Tech Support agents may be able to walk you through it.