Brother HL 1240 - B/W Laser Printer 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%
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;
<How to calculate drum unit life>
**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
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,
Page Counter'
Drum Life
99.4%
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
and '4. How to Read the Maintenance
Fig. A-2
Hot start
14 / 14 = 1
(14 + 5) / 14 = 1.36
(14 + 5 x 15) / 14 = 6.36
Information'.
A-6
100%
Page counter
00000090909090909
MZ-L160003F000000
Maintenance
information
Page counter
16
'3. How to Read the
1
2