Brother International HL-1660E Service Manual - Page 31

4.4 Paper Jam Detection The printer has a registration sensor and a paper eject sensor at the paper outlet to detect whether the printed paper has been fed correctly. A paper jam is detected by whether the paper is present at the sensor at the check periods programmed in the engine CPU memory. If the engine CPU detects a paper jam, the main motor, paper feed motor and scanner motor is turned off immediately and the jam status is transmitted to the video controller circuit. A paper jam is detected in any of following conditions: 1) Paper exists at the paper ejection sensor or the registration sensor when power is switched on. (JAM REAR or JAM INSIDE) 2) Paper has not reached the registration sensor within a specified time (JAM TRAYS). 3) Printed paper has not passed through the registration sensor within a specified time (JAM INSIDE (1) ). 4) Printed paper has not reached the paper ejection sensor within a specified time (JAM INSIDE (2) ). 5) Printed paper has not passed through the paper ejection sensor within a specified time (JAM REAR). Jam tray STBY PRINT Main motor Pick-up solenoid Registration sensor Jam check Jam inside (1) STBY 3.75 sec Normal 3.75 sec Jam Figure 2.21 PRINT Main motor Paper feed motor Registration sensor Jam check 3.67 sec 3.67 sec Jam Normal Figure 2.22 II - 15