HP M3027 Service Manual - Page 81

Timing The microprocessor on the ECU controls the device operation sequences. Table 4-1 Operation sequences on page 69 describes engine operations for each period of a print operation. Figure 4-19 Operational sequences on page 70 provides a graphical representation of the operation sequences. Table 4-2 Power-on sequence on page 72 describes each step of the power-on sequence. Table 4-3 Power-on sequence for the ADF/scanner assembly on page 72 describes the ADF power-on sequence. Table 4-1 Operation sequences Name Timing Purpose WAIT From power-on until the end of the main motor initial Detects presence of a print cartridge. Clears potential drive from the drum surface and cleans the transfer roller. SeeTable 4-2 Power-on sequence on page 72 for a complete description of the WAIT (power-on) period. Also see Figure 4-20 Timing diagram, HP LaserJet M3027/M3035 on page 71 for detailed information about device timing. STBY (standby) From the end of the WAIT or LSTR period until either Prepares the device to receive print commands a print command is sent from the formatter or the power is turned off. INTR (initial rotation) From the time of the print command until the pickup Prepares the photosensitive drum for printing. solenoid is turned on. PRINT From the end of the INTR period until the top-of-page Forms the image on the photosensitive drum and sensor detects the trailing edge of the media. transfers the toner image to the media. LSTR (last rotation) From the end of the PRINT period until the main motor stops rotating. Delivers the last page of a print job. After LSTR, the device either returns to STBY or, if another print command was sent from the formatter, enters INTR. ENWW Timing 69