Altering Volume factory settings on ONN tv model KL26AS25Q?

I was operating my Onn TV model: KL26AS25Q remote control went it somehow sent a spurious signal and entered 'FACTORY SETTING MODE', how I dont know but in my panic I inadvertantly altered a setting which now means that my volume stays the same throughout the entire 1 to 60 range '0' mutes. Please help me to get back into the factory setting and from then on I will be able to understand and reset the required perameters. thanks