Canon NP6251 Reference manual

SERVICE BULLETIN COPIER
NP6251
MODEL:
Major quality issues
Field quality problems
Quality upgrade/production efficiency
Miscellaneous
LOCATION:
SUBJECT:
Issued by Canon Europa N.V.
LENS MOUNT
ADJUSTING IMAGE AFTER REPLACING THE LENS STAGE
Outline
Notification is made here of how to perform adjustment if for the reason of problem with the lens a lens
stage has been replaced, and then after this replacement the lens fails to yield good resolution.
Lens stage replacement procedure (refer to the Service Manual)
1) Disconnect the plug and remove the copyboard glass and lens hood.
2) Move the mirror 1 mount to the right and remove the stage wire fixture (1in Figure 1; 2 locations).
3) Remove the lens stage cable (2in Figure 1, Figure 2 enlargement; connector, ground wire).
After replacing the lens stage, attach the cable following the same path as before so that the movement of
the lens stage is not affected.)
4) Move the mirror 1 mount to the left direction.
5) Remove the light blocking curtain (3in Figure 1; 2 locations)
The light blocking curtain is pasted to the lens with two-sided tape; be careful when peeling off the light
blocking curtain so as to avoid tearing it (enlarged Figure 3). After replacing the lens stage, re-attach it
with a two-sided tape.
6) Remove the sheet guide (1) (4in Figure 1).
Sheet guide (1) is also attached to the new lens stage but since the light blocking sheet needs to be pasted
again, it is advisable to reuse the removed sheet guide.
7) Lift the left side of the lens stage and remove the bushing (5 in Figure 1) from the rail (2 locations).
8) After replacing the lens stage with a new one, attach the removed parts.
- 1/4 -
Fig. 1 Lens mount
Mirror mount 1
2
1
5
3
4
No.: 6251-001
(H2-12E-036)
DATE:30.01.98

Adjustment for obtaining good resolution
1) Set the lens position for DIRECT copying (power ON position).
2) Turn the power OFF and unplug the cord.
3) Remove the copyboard glass and lens cover.
4) Insert a jeweler's screwdriver (diameter: 2 mm) or hex wrench (1.5 mm) into the side hole of the lens
(diameter: 2 mm). At this time, the tip of the screwdriver must go through the oval hole on the cam plate
located under the side hole. (See Figures 4 and 5.)
- 2/4 -
6251-001
Fig. 2 Lens stage cable (enlargement) Fig. 3 Light blocking curtain (enlargement)
Fig. 4 Lens stage Fig. 5 Detailed side hole section
Cable clamp
Ground cable
Jeweler's screwdriver
Lens
Side hole section Cam plate Cam plate oval hole
Lens round hole
(2 mm in diameter)
Connector Remove the light blocking
curtain hooked here. Shaded part is attached with two-sided tape; peel it off.

- 3/4 -
6251-001
5) If the screwdriver does not go through the oval hole on the cam plate, loosen the fixing screw of the cam
plate and move the cam plate in the Y direction, then put the screwdriver through the oval hole. (See
Figures 6 and 7.)
6) With the screwdriver through the oval hole, tighten the cam fixing screw by lightly pressing the cam shaft
(shaded part of Figure 8) against the side of the rail (toward the lens).
7) After attaching the removed parts, turn the power switch ON and check the image for DIRECT copying.
If good resolution is not obtained, repeat Steps 1 to 6 again. When good resolution is obtained, bond lock
the cam plate fixing screw.
Fig. 8 Fixing cam shaft
Fig. 6 Lens stage Fig. 7
Positional relationship of round hole and oval
hole when the lens side hole is seen from the top
Y direction
Cam plate Cam plate
fixing screw
Cam plate
fixing screw
Cam shaft
Lens
Oval
hole Round hole
OK NG NG

- 4/4 -
6251-001
8) Check enlarged and reduced images
If enlarged or reduced images show that the lens fails to yield good resolution, loosen the image
enlargement (or reduction) lens rail fixing screw and bend the rail to either one of Y direction and tighten
the fixing screw. (See Figure 9.)
Check images again and if the lens still fails to yield good resolution, bend the rail in the opposite
direction.
When good resolution is obtained, bond lock the lens rail fixing screw.
Fig. 9 Lens rail
Service Parts
NP6251
P.C.
210-
Old
New
Old
1New
No. Description Part number Q’ty
0 →1
FG5-9408-000Stage, lens
Inter-
change-
ability
❈1
Y direction
Rail fixing screw (200% enlargement)
Lens rail
Rail fixing screw
(50% reduction)

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SERVICE BULLETIN COPIER
NP6251
MODEL:
Major quality issues
Field quality problems
Quality upgrade/production efficiency
Miscellaneous
LOCATION:
SUBJECT:
Issued by Canon Europa N.V.
DECK PICK-UP ASSEMBLY
IMPROVEMENT TO DURABILITY OF SEPARATION ROLLER
Outline
A bearing has been added to the separation roller support to improve the roller durability.
Details
[Phenomenon]
Paper pick-up fault
[Cause]
The sponge part of the separation roller becomes damaged because of a decrease in durability.
[Factory measures]
A bearing has been added to the separation roller support .
Measures for servicing
If the above phenomenon occurs, replace the parts below or the deck pick-up assembly.
- 1/3 -
FB2-7602-000 (replace)
New partOld part
Deck right pick-up assembly
FF5-3213-000 (replace)
FB3-9207-000
FF5-6397-000
XG9-0243-000 (new)
FB3-9207-000
FS6-2678-000
FB2-7602-000 (replace)
FS5-2983-000 (replace)
No.: 6251-003 Rev. 1
(H2-12E-033)
DATE: 24.07.98

- 2/3 -
6251-003 Rev. 1
Old part New part
Deck left pick-up assembly
Service parts
P.C.Old
New
Old
1
2
3
4
5
Old
Old
Old
Old
New
New
New
New
New
No. Description Part number Q’ty
2 →0
0 →2
1 →0
0 →1
1 →0
0 →1
0 →1
1 →0
0 →1
FB2-7602-000
FB3-9207-000
FF5-3213-000
FF5-6397-000
FS5-2983-000
FS6-2678-000
XG9-0243-000
FG5-5801-020
FG5-5801-170
Arm, roller
Arm, roller
Shaft, separation
Shaft, separation
Spring, tension
Spring, tension
Bearing
Deck right pick-up ass’y
Deck right pick-up ass’y
Inter-
change-
ability
❈1
❈1
❈1
❈1
No Yes
❈1 Interchangeable by replacing all 4 parts at the same time.
FB2-7709-000 (replace)
XD2-1100-402 (eliminated) FB3-9207-000
FF5-6397-000
XG9-0243-000 (new)
FB3-9207-000
FS6-2678-000
FB2-7709-000 (replace)
FS5-2984-000 (replace)
FF5-6406-000
FF5-3213-000 (replace)
XD2-1100-402 (eliminated)
FB2-7708-000 (replace)
FB2-7714-000 (eliminated)
312-8
312-41
312-52
312-
312-

- 3/3 -
6251-003 Rev. 1
Service parts
P.C.Old
New
Old
6
7
8
9
10
11
Old
Old
Old
Old
Old
New
New
New
New
New
New
No. Description Part number Q’ty
2 →0
0 →2
1 →0
0 →1
1 →0
0 →1
2 →0
0 →1
1 →0
0 →1
FB2-7709-000
FB3-9207-000
FF5-3213-000
FF5-6397-000
FS5-2984-000
FS6-2678-000
XD2-1100-402
XG9-0243-000
FG5-5804-000
FG5-5804-120
Arm, separation, left
Arm, separation
Shaft, separation
Shaft, separation
Spring, tension
Spring, tension
Ring, E
Bearing
Deck left pick-up assembly
Deck left pick-up assembly
Inter-
change-
ability
❈2
❈2
❈2
❈2
❈2
No Yes
Affected Machines (“LPS version”)
Deck right pick-up assembly
CJB 00001 and later
DJB 00001 and later
Deck left pick-up assembly
CJB 01881 and later
DJB 00571 and later
313-16
313-31
313-39
313-505
313-
313-
❈2 Interchangeable by replacing all parts at the same time.

- 1 / 2 -
Service Bulletin
Issued by Canon Europa N.V.
Model : NP6251 No.: 6251-004 Rev. 1
(FF-T01-H2-000006-01)
DATE: 24.07.98
Location : WASTE TONER DRIVE ASSEMBLY (FIXING ASSEMBLY)
Subject : CRACKING OF 49T PULLEY
Reason : To prevent cracking of the 49T pulley belonging to the fixing assembly waste toner drive assembly,
this pulley has been changed to a stronger type.
Details : [Phenomenon]
Jamming of the paper reaching the fixing assembly.
[Cause]
Cracking of the 49T pulley of the fixing assembly waste toner drive assembly.
[Factory measures]
The 49T pulley has been changed to a stronger type.
Old New
Fig. 49T pulley
Servicing : When the aforementioned phenomenon occurs, replace the old type 49T pulley with the new type 49T
pulley.
COPIER

6251-004 Rev. 1
- 2 / 2 -
Service Parts :
No. Description Part number Q’ty Inter-
change-
ability
P.C.
-- -- -- -- -- -- -- --
1 Old PULLEY, 49T FS2-3493-030 1

0280-13
New PULLEY, 49T FS6-0864-000 0

1
2 Old WASTE TONER DRIVE ASSEMBLY FG5-8721-070 1

0 280-
New WASTE TONER DRIVE ASSEMBLY FG5-8721-080 0

1
Affected machines
(
“Ja
p
anese version”
)
NP6251
NHU00039 and later
NGT00005 and later
NJE00001 and later
Affected machines (“LPS version”) 
NP6251
CJB00701 and later
DJB00283 and later
No Yes
No Yes