09/2007
6-16
Phaser 8860/8860MFP Service Manual
Print Engine Check Menu Tests
Initial Issue
Diagnostics
Wiper Shaft Test
This test exercises the Head Maintenance Clutch and Wiper Assembly. The test raises the
wiper to just under the tilt engage point, and then moves the wiper to home position to initialize
the drive mechanism. Next, the Printhead is tilted back out of the way and the Media Drive
Assembly is driven for a short time. While the Media Drive Assembly is being driven, the Head
Maintenance Clutch is engaged. Finally, the clutch is released and the Media Drive Assembly
is stopped. This process repeats for the opposite direction.
If the Printhead does not tilt to the Standby position, the Wiper Blade will interfere with the
Printhead causing error in the recorded values. The system response to the Head Mainte-
nance Clutch activity demonstrates the clutch characteristics. Steady state drive values indi-
cate bearing status and the condition of the pulleys, belts, and shafts. The CW and CCW
measurements are slightly different due to the vertical motion of the Wiper Assembly. The data
used is the Media Drive Assembly servo system following error (fe), which is a measure of how
hard the system is working at any point in time.
2 CCW On fe settling time (sec) N/A Reports the time it takes the MP motor
servo system to settle down after the
sudden addition of the deskew shaft
load. A longer time could indicate a loose
deskew shaft or a slipping clutch.
3 CCW On average fe N/A Reports the average effort required to
rotate the deskew shaft in the CCW
direction at a constant velocity. An
unusual value could indicate a difference
in the composition and/or number of the
rollers, the nip pressure, or out of range
mechanical dimensions due to wear or
contamination (such as paper dust
increasing the effective diameter of a
roller).
4 CCW On fe ripple N/A Reports the variation of effort required to
rotate the deskew shaft in the CCW
direction at a constant velocity. A larger
value could indicate particles in the
gears or non uniform contamination of a
roller (causing a lump).
5 CCW Off fe settling time (sec) N/A Reports the time it takes the Media Drive
Motor servo system to settle down after
the sudden release of the deskew shaft
load. A larger value can indicate a slow
to release or dragging clutch.
6 Time to CW On peak fe (sec) N/A Reports a time that indicates how long it
takes the MP motor servo system to
react to the sudden addition of the
deskew shaft load. Larger values may
indicate a slipping or slow to engage
clutch.
7 CW On peak fe N/A Reports the peak effort required to accel-
erate the deskew shaft load. A smaller
value could indicate a slipping clutch.
8 CW On fe settling time (sec) N/A Reports the time it takes the MP motor
servo system to settle down after the
sudden addition of the deskew shaft
load. A longer time could indicate a
looseness in the deskew shaft assembly
or a slipping clutch.
Table 10 Deskew Shaft Nominal Values
R# Characteristic Typical Value Result
9 CW On average fe N/A Reports the average effort required to
rotate the deskew shaft in the CW direc-
tion at a constant velocity. An unusual
value could indicate a difference in the
composition and/or number of rollers, the
nip pressure, or out of range mechanical
dimensions due to wear or contamina-
tion (such as paper dust increasing the
effective diameter of a roller).
10 CW On fe ripple N/A Reports the variation of effort required to
rotate the deskew shaft in the CW direc-
tion at a constant velocity. A larger value
could indicate particles in the gears or
non uniform contamination of a roller
(causing a lump).
11 CW Off fe settling time (sec) N/A Reports the time it takes the MP motor
servo system to settle down after the
sudden release of the deskew shaft load.
A larger value could indicate a dragging
or slow to release clutch.
Table 11 Wiper Shaft Nominal Values
R# Characteristic Typical Value Result
0 Time to CCW On peak fe
(sec)
N/A Reports how long it takes the Media
Drive Assembly servo system to react to
the sudden addition of the wiper shaft
load. Larger values may show a slipping/
slow to engage clutch.
1 CCW On peak fe N/A Reports peak effort needed to accelerate
the wiper shaft load. A smaller value
could indicate a slipping clutch.
Table 10 Deskew Shaft Nominal Values
R# Characteristic Typical Value Result
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