Canon LBP-CX Series Service Manual page 6

CHAPTER 7 TROUBLESHOOTING
I.
INTRODUCTION
A. Initial Check .................. 7- 1
B. Basic Procedure ............... 7- 1
H. CHECK/ ADJUSTMENT
A. Printer Driver and Laser Driver
Checker Operation ............. 7- 2
B.
Image Adjustment
1. Basic image adjustment ......... 7- 3
2. Adjusting the height of the transfer
corona wire .................. 7- 3
C. Mechanical Adjustment
1. Adjusting the cassette spring
lifting force .................. 7- 3
2. Adjusting the fixing rollers
(nip width) ................... 7- 3
D. Electrical Adjustment
1. LEDs and VR settings .......... 7-
5
2. Checking the DC controller and AC
driver (AC controller and the fixing
roller heater safety circuits) ...... 7-
5
3. Adjusting laser power ........... 7- 7
lli. IMAGE DEFECTS
A. Examples oflmage Defects ...... 7-13
B. How to Read the Troubleshooting
Tables ....................... 7-14
C. Troubleshooting Image Defects
I-1. Light image ................ 7-15
I-2. Dark image ................. 7-16
I-3. Blank print ....•............ 7-17
1-4. Black image ................ 7-18
I-5. Stained separation strip ....... 7-18
I-6. Stains on back of paper ....... 7-19
I-7. Dark vertical lines
(paper feed direction) ......... 7-19
I-8. Sharp horizontal black lines (cross
feed direction) .............. 7-20
I-9. Vertical fogged stripes
(paper feed direction) ......... 7-20
I-10. Horizontal fogged stripes
(cross feed direction) ......... 7-20
I-11. White horizontal lines or other
shapes on a black print ........ 7-21
I-12. Thin vertical white lines or stripes
(paper feed direction) ......... 7-21
1-13. Faulty registration ........... 7-22
I-14. Poor fixing ................. 7-22
I-15. Distortion .................. 7-23
I-16. Waviness ................... 7-23
IV. TROUBLESHOOTING
MALFUNCTIONS
M-1. There is no power ............ 7-24
M-2. The main motor does not
rotate ..................... 7-27
M-3. The high-voltage power supply does
not provide power ........... 7-27
M-4. The fixing roller heater does not
operate .................... 7-28
M-5. Cannot feed paper manually .... 7-29
M-6. Paper is not fed from
the cassette ................. 7-30
M-7. Jam are detected when there are
no jams .................... 7-31
M-8. Jams are not detected ......... 7-31
M-9. The PAPER OUT indicator lights
when there is still paper ....... 7-32
M-10. The PAPER OUT indicator does
not light when there is no
paper ..................... 7-32
M-11. The preconditioning exposure lamps
do not light ................ 7-34
M-12. Laser, scanner malfunction ..... 7-34
M-13. Heater malfunction .......... 7-35
M-14. All LEDs on the display panel
do not light ................ 7-36
M-15. The READY /WAIT indicator does
not stop flashing ............. 7-37
M-16. The READY/WAIT indicator does
not light ................... 7-37
M-17. Printing does not start when a TRUE
print command (PRNT)
is input .... ' ................ 7-37
V. PAPER TRANSPORT PROBLEMS
(A jam occurs every time paper is fed.)
A. Paper Jams
T-1. Manual feed unit .....
~
...... 7-39
T-2.
Cassette pickup assembly ...... 7-39
T-3. Separation/feeder unit ........ 7-39
T-4. Fixing/delivery area .......... 7-40
B. Incomplete Feed
T-1. Sheets stuck together ......... 7-40
T-2. Wrinkles ................... 7-40
VI
COPYRIGHT
©
BY CANON INC. CANON LBP·CX SERIES REV.2 JULY 1985 PRINTED IN JAPAN (IMPRIME AU JAPONI