Pixma G4210 - no test print grid

[snowandginger]

All of a sudden, my printer will not print anything except gradients. When I print a test sheet, all I get is (two thirds of the way down the page) an emply C with "Unix Printing System" inside it, a little circular color wheel, and part of a gray gradient bar. No grid at the top at all, even though the colors are obviously printing out in the color wheel.

All inks are almost full.

When I go into "supply levels" I get the message "information not available".

I don't see any way to clean heads using the software on my cumputer.

Help! 

[snowandginger]

I am on a Mac. When I go into System Preferences - Printers and Scanners- Utility - Open Printer Utility- Test Print - Nozzle check - Print Test Pattern, I get the message "The executed process is in a standby condition. Check the print queue". There is nothing in the print queue.

So, I can't print a test print this way. I have tried to do it by selecting the Canon printer icon then using the pull down menu (Printer- Print test page).