HP LaserJet 5000 Service Manual - Page 295

Image System Troubleshooting Half Self-Test Functional Check The electrophotographic process can be subdivided into the following stages: q Cleaning (removes excess toner from drum surface) q Conditioning (places a uniform electrical charge on drum) q Writing (laser strikes surface of drum to create latent image) q Developing (forms the toner image on drum) q Transferring (charges transfer the image to paper) q 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: 1 Print a Configuration Page from the Control Panel INFORMATION MENU. 2 Open the top cover after the paper advances half-way through the printer (about five seconds after the Main Motor begins rotation). The leading edge of the paper should have advanced past the Toner Cartridge. 3 Remove the Toner Cartridge. 4 Open the Toner Cartridge's drum shield to view the drum's 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 - see Chapter 5), and troubleshoot the failure as a transfer or fusing problem. If no image is present on the photosensitive drum, perform all the following functional checks: 7-74 Troubleshooting EN