Half self test functional check The electrophotographic process can be subdivided into the following stages: Cleaning (removes excess toner from drum surface) Conditioning (places a uniform electrical charge on drum) Writing (laser strikes surface of drum to create latent image) Developing (forms the toner image on drum) Transferring (charges transfer the image to paper) Fusing (heat and pressure produces a permanent image) The purpose of the half self test check is to determine which process is malfunctioning. Perform the test as follows: Step 1 Print a configuration page from tray 1. Step 2 Open the top cover after the trailing edge of the paper enters the printer.
At this point, the leading edge of the paper should have advanced beyond the toner cartridge. Step 3 Remove the toner cartridge. Step 4 Open the toner cartridge drum shield to view the drum surface. If a dark and distinct toner image is present on the drum’s surface, assume that the first four functions of the electrophotographic process are functioning (cleaning, conditioning, writing, and developing) and troubleshoot the failure as a transfer or fusing problem. If no image is present on the photosensitive drum, perform the drum rotation functional check. Drum-rotation functional 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. To verify whether the drum is rotating: 1 Open the top cover. 2 Remove the toner cartridge. 3 Mark the cartridge drive gear with a felt-tipped marker. Note the position of the mark. 4 Install the toner cartridge and close the top cover. The start-up sequence should rotate the drum enough to move the mark. 5 Open the printer 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 it is meshing with the toner cartridge gears. If the drive gears function and the drum does not move, replace the toner cartridge.
Note This test is especially important when the customer is using refilled toner cartridges. 208 Chapter 7 Troubleshooting C7058-90936