Brother 09055CDN, Service Manual

Page: 55 / 590

2-16
Confidential
■ Life of drum unit
<How to read the drum unit life>
- It initially indicates 100% and gradually decreases.
- It indicates 10% when the “Replace Parts Drum” appears on the LCD.
<How to calculate the drum unit life>
The drum unit life is based on the “drum counter” or the “number of drum rotations.” The
drum counter is based on the total printed pages on each drum unit. This total printed
pages should be reset every time you replace the drum unit with a new one. (Refer to
“2.2
Parts Life Reset Function” in Chapter 5 .) Basically this amount is equal to the assured
printable pages of the drum unit. If the developing bias voltage correction or color
registration adjustment is performed frequently, however, only the number of drum
rotations increases, and the “page counter based on the number of drum rotation”
exceeds the “drum counter” based on the total printed page.
Refer to the calculation of the drum unit life based on the number of drum rotation below;
<How to calculate the page counter>
The number of drum rotations for the first page printed is about 24.
The number of drum rotations per one page for the second or later page printed
(continuous printing) is 3.6.
Page counter based on the number of drum rotations = {Number of drum rotations for the
first page p [Number of drum rotations per one page for the second or later page
printed x (Number of pages in continuous printing - 1)]} / 24
(* The number of drum rotations per one page continuous printing.)
Example: Starts to print when the machine is in the Ready state.
If you leave the machine without printing for a long time, the number of drum rotations is
increasing because the developing bias voltage correction and the color registration are
performed. If you print one page per one job every time after leaving the machine without
printing for a long time, the drum unit life is shorter than usual.
The number of drum rotations required for the developing bias voltage correction = 68 rotations.
Example: Performs the developing bias voltage correction and starts to print after leaving
the machine without printing for a long time.
The number of drum rotations required for the color registration = 35 rotations
Example: Performs the color registration adjustment and starts to print after leaving the
machine without printing for a long time.
Continuous printing Page counter based on the number of drum rotations (Pages)
1 page/job {24 + [3.6 x (1 - 1)]} / 24 = 1
2 pages/job {24 + [3.6 x (2 - 1)]} / 24 = 1.15
18 pages/job {24 + [3.6 x (18 - 1)]} / 24 = 3.55
Continuous printing Page counter based on the number of drum rotations (Pages)
1 page/job {68 + 24 + [3.6 x (1 - 1)]} / 24 = 3.83
2 pages/job {68 + 24 + [3.6 x (2 - 1)]} / 24 = 3.98
18 pages/job {68 + 24 + [3.6 x (18 - 1)]} / 24 = 5.38
Continuous printing Page counter based on the number of drum rotations (Pages)
1 page/job {35 + 24 + [3.6 x (1 - 1)]} / 24 = 2.45
2 pages/job {35 + 24 + [3.6 x (2 - 1)]} / 24 = 2.61
18 pages/job {35 + 24 + [3.6 x (18 - 1)]} / 24 = 5.03