Canon BJC 3000 Reference Manual page 239

Check 1
Is the ink of BJ Cartridge in good condition?
The print head nozzles may be clogged, one or more of the ink tanks may
be low, or the BJ Cartridge may be worn.
Visually check the level of the ink in the ink tanks. If the tanks are empty,
replace them.
Next, print a nozzle check pattern to check the status of the print head and
clean the print head.
If the problem is not solved, replace the BJ Cartridge.
If you can print a nozzle check pattern normally, check that the printer is
connected to the computer securely. If the connection is loose, printing
starts but nothing may be printed.
Also check that there is no problem with the original file.
Printing a Nozzle Check Pattern
Cleaning the Print Head
Replacing the Ink Tanks
Replacing the BJ Cartridge
Troubleshooting - Printer Does Not Start or Stops in Mid-job
Printing starts but nothing printing
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