HP 1300 Service Manual - Page 71

Basic sequence of operation (formatter-toprinter) The operation sequence of the printer is controlled by the microprocessor (CPU) on the ECU. The following events take place during normal printer operation: Table 12. Basic sequence of operation Period WAIT After the printer is turned on until the end of the initial rotation of the main motor. STBY (Standby) From the end of the WAIT period or the LSTR period until the pickup command is input from the formatter. Or, from the end of the LSTR period until the printer is turned off. INTR (Initial Rotation Period) After the pickup command has been input from the formatter until the media reaches the pickup solenoid. PRINT (Print) From the end of the initial rotation until the primary voltage goes OFF. LSTR (Last Rotation Period) After the primary voltage goes OFF until the main motor stops rotating. Purpose To clear the drum surface of electric potential and to clean the transfer charging roller. To keep the printer ready to print. To stabilize the photosensitive drum sensitivity in preparation for printing. Also to clean the transfer charging roller. To form images on the photosensitive drum based on the VIDEO signals (/VDO, VDO) input from the formatter and to transfer the toner image onto the media. To deliver the last page. Also to clean the transfer charging roller. Remarks Detects whether or not the cartridge is installed. When the pickup command is input from the formatter, the printer enters the INTR period immediately after the end of the LSTR period. ENWW Printer functions 71