HP LaserJet 5000 Service Manual - Page 136

Basic Sequence of Operation The Formatter PCA and the DC Controller Board share information during printer operation. The Interface PCA forms a link which operates as a serial data bus. This allows printer status, command, and dot-image data to be passed between the two PCAs. Table 5-1 shows the general timing of the printer events. The following events take place during normal printer operation: Table 5-1. Printer Timing Period Timing Purpose Remark WAIT From power on until the Main Motor completes the initial drive. Clears the drum surface potential and cleans the transfer charging roller. During this period, the printer detects the toner level and the presence of the cartridge. STBY (standby) From the end of the WAIT Makes the printer ready to period until the /PRNT print. signal is input from the Formatter, or from the end of the LSTR period until the /PRNT signal is input from the Formatter or until the power is turned off. INTR (initial rotation) After the /PRNT signal is input from the Formatter until the DC controller outputs the /TOP signal. Stabilizes the sensitivity of the photosensitive drum in preparation for printing, and cleans the transfer charging roller to stabilize the transfer high voltage. PRINT From the end of the INTR period until the top of the paper sensor detects the trailing edge of the paper. Forms an image on the During this period, photosensitive drum the printer detects according to the /VDO the remaining toner. and VDO signals input from the video controller, and transfers the image to paper. EN Basic Sequence of Operation 5-45