Brother International HL 1240 Service Manual - Page 164

APPENDIX 2. How to Read the Drum Unit Life The drum unit life is shown by the bar at the bottom of Print Configuration as follows; It initially indicates 100% and gradually decreases. It indicates 0% when the Drum LED is on. It stays at 0% even if further printing is done. 0% Drum Life 100% Page counter 99.4% Fig. A-2 00000090909090909 MZ-L160003F000000 Maintenance information The drum unit life is based on the page counter. If the average number of drum rotations is more than the number of drum rotations in non-continuous printing, however, the drum unit life is counted by the number of drum rotations. Since the drum counter printed in Print Configuration is an actual page counter after a new drum unit is replaced, the drum unit life may be different from the drum counter. For details on the difference between the drum unit life and drum counter, refer to the drum unit life calculation below; **Printing time for 1 page/job in discontinuous printing = 14 seconds (Page counter reduced the number of drum rotation) = (Time of motor rotation) ÷ (14 sec.) Example: 1 page/job 2 pages/job 16 pages/job Cold start (Idling for 6 sec.) (6 + 14) / 14 = 1.43 (6 + 14 + 5) / 14 = 1.79 (6 + 14 + 5 x 15) / 14 = 6.79 Hot start 14 / 14 = 1 (14 + 5) / 14 = 1.36 (14 + 5 x 15) / 14 = 6.36 Page counter 1 2 16 If printing 1 page per job with cold start, the drum unit life is decreased earlier. NOTE: For the numbers at the right below of the bar, see the following sections, '3. How to Read the Page Counter' and '4. How to Read the Maintenance Information'. A-6