HP LaserJet 1100 Service Manual - Page 137

If the memory is too low, a reduced Self Test Page is printed which contains only the printer configurations and a message "Reduced Self Test Printed - Memory Too Low." In a lowmemory condition the font printout attempts to print all downloaded permanent fonts, but if the memory is too low a message "Font Test Aborted" is printed. In some low-memory situations a reduced Self Test Page may be printed, but the font printout may have enough memory to print all downloaded permanent fonts. Half-self test functional check The electrophotographic process can be subdivided into the following stages: • Image formation stage (charges the drum and writes a latent image to the drum with the laser) • Development stage (forms a toner image on the drum) • Transfer stage (transfers the image to paper) • Cleaning stage (removes excess toner from the drum) • Fixing stage (applies heat and pressure to make the image on paper permanent) The purpose of the half-self test check is to determine which process is malfunctioning. Perform the test as follows: 1 Initiate a self test. 2 Open the printer door after the paper advances half-way through the printer (about 8 seconds after the 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 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 fixing problem. If there is no image on the photosensitive drum, perform the following functional checks: 1 Make sure you have removed the entire length of the sealing tape from the toner cartridge before you installed the cartridge. 2 Perform a drum rotation functional check. 3 Perform a high-voltage power supply check. 142 Troubleshooting/Maintenance C4224-90962