Canon LASER CLASS 730i Service Manual page 91

LASER CLASS 730i/720i/710 Chapter 4: Maintenance and Service
3. ADJUSTMENT
3.1 Checking the Nip Width of the Pressure Roller
The fixing unit is not designed to allow adjustment of the pressure (nip width); however, the
incorrect nip width can cause fixing problems.
Follow the procedures below to check the nip width:
(1) Either take along one or two all-black copies of A4 or letter size made with a
copier, or make it using a copier at the customer site.
(2) Place the all-back copy in the cassette of the printer, with the printed side facing
down.
(3) Open the face-up tray.
(4) Press the test print switch (SW801) on the EPU board.
(5) When the leading edge of the print emerges at the face-up tray, turn OFF the
printer.
Take out the print from the printer about 10 seconds later.
(6) Measure the width of the glossy band across the paper and check that it meets the
requirements as shown in below table.
c
Paper feed direction
a
b
a
b - a
c - a
b - c
Figure 4-7 Fixing Nip Width
10 mm
Center
10 mm
Dimension
6.0 to 7.5 mm
0.6 mm or less
0.6 mm or less
0.5 mm or less
4-8