Hi Hau Hoang, good question! This is unfortunately not as easy as just holding a button down while turning on. PreSonus gives a detailed guide on how to achieve this here: support.presonus.com/hc/en-us/articles/210047893-StudioLive-AI-Mixer-Firmware-Recovery-Factory-Reset Let me know if there is anything else I can help with! Drake Sobehrad, Sweetwater Sales Engineer, (800) 222-4700 ext. 3271, drake_sobehrad@sweetwater.com
