Canon BJC-3000 - Manual (Page 241)

241 Troubleshooting - Printer Does Not Start or Stops in Mid-job
Cartridge holder does not move to the left side
You want to switch the BJ Cartridge, replace an ink tank, or replace the BJ Cartridge, but
the cartridge holder does not move to the left side when you open the front cover.
Check 1 Is the printer switched on?
Check 2 Has the front cover been open longer than 10 minutes?