Some enterprise units pre-configured by third-party dealers use the serial number as the default. Others use admin as the username (though the WF-C5790 typically just asks for a numeric password on the touchscreen). What If the Default Doesn't Work? (The "Invalid Password" Error) If you see "Invalid Password" or "Wrong Password," someone has already set a custom password. This is common in offices where an IT department initially set up security policies. When that IT person leaves without documenting the password, the printer becomes a brick wall.
You have three options: Use Epson Remote Configuration, perform a partial reset, or execute a full factory reset. This method resets only the network and admin password settings while preserving your address book, print counters, and job logs. epson wfc5790 admin password
Remember: security and convenience are trade-offs. The moment you regain access, store that password somewhere safe—not on a sticky note attached to the printer. This guide is for legitimate administrator use only. Attempting to bypass security on devices you do not own may violate local laws and Epson’s terms of service. (The "Invalid Password" Error) If you see "Invalid