How to Perform the Self-Tests and Diagnostic Tests

NOTE: There are two keys on the front panel of the printer. The top key is the Form Feed key and light. The bottom key is the Power key and light.

Printing a Self-Test

Preparing for the self-test procedure:

Be certain that the printer is not connected to an active Input/Output (I/O).
Make certain that both print cartridges are properly installed, and that the cover to the printer is completely closed.

Procedure to run the self-test with the printer on:

With the Power light lit, push and hold the Power key while pressing the Form Feed key four times.
Release the Power key.

Procedure to run the self-test from the HP DeskJet 820C ToolBox:

Select the HP DeskJet Utilities icon in Program Manager.
Select the HP DeskJet 820C ToolBox.
Select Printer Services.
Select Print a Self Test page.

Diagnostic Test

The printout for the Clean the Print Cartridges routine contains several diagnostic tools useful for isolating and resolving printer problems.

Procedure to print the Clean the Print Cartridges routine:

Select the HP DeskJet Utilities icon in Program Manager.
Select the HP DeskJet 820C ToolBox.
Select Printer Services.
Select Clean the Print Cartridges to begin the clean routine.

The clean routine produces a printout with the information in the table below.

TEST	PURPOSE
Missing Dot Tests (Black and Color)	To verify that all dots of the installed print cartridges are firing correctly. Six diagonal lines of black are printed to test the black print cartridge, then one line each of cyan, magenta, and yellow are printed to test the color print cartridge (natural light helps in evaluating the yellow test). The test is repeated at the bottom of the page. If a gap appears along one of the diagonal patterns, one or more dots are not firing.
Model Number	Verifies correct printer driver.
Pen Cleaning Bands	These bands are remnants of the pen cleaning routine. The upper band should be dark gray (black composite using only the color print cartridge). The next band should be solid black (black print cartridge only), and the remaining bands should be cyan, magenta and yellow (the individual colors of the color print cartridge). Note: Waitbanding will not be revealed by this test.
Fonts Test	A scaled font (17 sizes of the letter A), followed by six additional fonts. Look for clarity, readability, and the absence of smearing. See "Printer Problems/Miscellaneous Printing Problems."
Color print cartridge test	Seven color bars are presented here to verify color print cartridge performance. The colors from left-to-right are: fully-saturated red, magenta, blue, cyan, green, yellow, and red (repeated). Verify the correct appearance of the colors. If not correct, change the color print cartridge.
Black print cartridge tests - 5 total. (Magnification may be helpful in evaluating these tests.)	The first three tests indicate interconnect and/or print cartridge problems.	1. Block Nozzle Test: Look for gaps in either the black or dark gray boxes. 2. Nozzle Pair Test: Each small horizontal line is actually two firing nozzles separated by a non-firing nozzle. Verify that each line-pair is present, that all lines are the same thickness, and that all pairs of lines appear evenly spaced and are not touching. 3. Nozzle Pointing Test: Verify that no lines appear to be paired together (results in a heavy line) The grid should have an even appearance.
	The remaining two tests detect carriage motion errors.	4. Vertical Line Test: In this test, all nozzles are fired simultaneously to form nine thin vertical lines. Verify all lines are clear and distinct, and all dots comprising the lines are aligned vertically. 5. Gray Bar Test: Five vertical gray bars test the nozzles ability to accurately reproduce grayscale tones. Verify no horizontal gaps in the gray bands are present.
Print Skew Test	The upper left and lower left corners of the printout contain the following: "\|=", and "\| \|=." To test for print skew, fold the self-test exactly in half so these corners are super-imposed. Hold the printout to the light and verify the single line touches or is inside the double lines. If not, see "Printer Quality Problems/Print Skew."