HP 2300d Service Manual - Page 230

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. Performing a half-self-test functional check 1 Print a configuration page from tray 1. 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 print cartridge. 3 Remove the print cartridge. 4 Open the print cartridge drum shield to view the drum surface. Interpreting the functional check 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. 228 Troubleshooting ENWW