HP LaserJet M476nw Pro Color MFP

Engine-test button

The engine test produces a single-sided sheet with horizontal lines when you perform the engine test.

To perform the test, use a small-pointed object, for example a straightened paper clip, to push the engine test button (accessed through a small hole in the rear cover). If the engine is functioning properly, the product will initialize and then print the test page.

Drum rotational check

The photosensitive drum, located in the toner cartridge, must rotate for the print process to work. The photosensitive drum receives its drive from the main drive assembly.

NOTE: This test is especially important if refilled toner cartridges have been used.

1. Open the toner-cartridge door.
2. Remove the toner cartridge.
3. Mark the drive gear on the cartridge with a felt-tipped marker. Note the position of the mark.
4. Replace the toner cartridge and close the toner-cartridge door. The startup sequence should rotate the drum enough to move the mark.
5. Open the toner-cartridge door and inspect the gear that was marked in step 3. Verify that the mark moved.

If the mark did not move, inspect the main drive assembly to make sure that it is meshing with the tonercartridge gears. If the drive gears appear functional and the drum does not move, replace the toner cartridge.

Half self-test functional check

The half self-test check determines which printing process is malfunctioning. This process requires you to stop the product while it is in the process of printing a page.

1. Print a Configuration page.
   a. From the Home screen on the product control panel, touch the Setup Setup button.
   b. Touch Reports.
   c. Touch Configuration Report to begin printing the report.
2. Open the toner-cartridge-door after the paper advances halfway through the product (about five seconds after the motor begins rotating). The leading edge of the paper should have advanced past the toner cartridge.
3. Remove the toner cartridge.
4. Open the toner-cartridge drum shield to view the drum surface. If a dark and distinct toner image is present on the drum surface, assume that the first two functions of the electrophotographic process are functioning (image formation and development). Troubleshoot the failure as a transfer or fusing problem.

If there is no image on the photosensitive drum, perform these checks:

1. Make sure you removed the entire length of the sealing tape from the toner cartridge before you installed the cartridge.
2. Perform a drum rotation functional check to make sure that the drum is rotating.
3. Make sure that the high-voltage contacts are clean and not damaged.