Service manual

5-13
Confidential
CAUTION:
• The drum unit life is shown by the band graph at the center of Printer Settings.
Drum Unit Life
How to Read the Drum Unit Life
- It initially indicates 100% and gradually decreases.
- It indicates 0% when the Drum LED is blinking.
- It stays at 0% even if further printing is done.
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 the drum unit. This total
printed pages should be reset every time you replace the drum unit with a new one.
(Refer to "2.1 User Maintenance Mode" in Chapter 5.) Basically this amount is equal to
the assured printable pages of the drum unit.
If under the situation with a little print number of sheets per one job, 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 15. The number of drum
rotations per one page for the second or later page printed (continuous printing) is 4.3.
Using these figures, the page counter is calculated as follows:
Page counter based on the number of drum rotations = (Number of drum rotations for
the first page printed + (Number of drum rotations per one page for the second or later
page printed x (Number of pages in continuous printing - 1)) / 15
(* 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. 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.
Continuous printing Page counter based on the number of drum rotations (Pages)
1 page/job (15 + (4.3 x (1 - 1))) / 15 = 1
2 pages/job (15 + (4.3 x (2 - 1))) / 15 = 1.29
18 pages/job (15 + (4.3 x (18 - 1))) / 15 = 5.87