If your printer locks you out, asks for passwords you never set and tells you that each and every WiFi and other option is locked by a Administrator then you need to reset that thing.

Mine always forgot the settings for WiFi and networking and DHCP and so on and one day he simply locked me out, disabled the network altogether and didn’t let me set anything through the touchscreen anymore.

Please enter the Pin… but i never set a pin…!

To unlock the “Disable Menu” option, press the touchscreen buttons in this way:

Home, Back, Home, Back
And enable all your settings you want (for example the Reset or Factory Restore option, which lets you reset the printer.

If this doesn’t help, you can shut down the printer with the power button, then restart it, pressing the Power Button and press a Finger on the Touchscreen at the same time, until the screen goes black.

There you can reset the machine.