All Canon Bubblejet printers be tested without a computer. In fact, most have several different test prints available.
A test print is the best way to insure that the printer hardware is working. If the printer prints a good test print, it usually does not need to be sent in for service. If it won't print a test print, nothing you do at your computer will work!
The most common way to get a print is to hold down the FF or FORM FEED button while the printer is powered off. (if you don't have a FORM FEED, try another button). Then, while holding the button... hit the POWER button to turn the printer on. The printer should go through it startup procedure and print a test page.
For other test prints, check your users manual. If you can't get a test print, call Landmark for the fastest repairs possible.