Hello Jeongho,
I see no one has responded to this post yet. So, at this point I would recommend contacting your local Xerox Support Department to speak with a Product Specialist for more assistance. You can visit our Contact Us page for support options in you location: https://www.xerox.com/en-us/about/contact-us Scroll down to the Worldwide Contacts and select your Country.
C2255 When the printer boots up, only the message'please wait' is displayed, and nothing works. Both red and green lights blink.