5–4TROUBLESHOOTING FEEDING FAULTS4 Duplexing Unit (during stacking operation)CauseDuplexing unit inletsensor (PS15)Set-back motor(M5)RemedyReplace the sensor.Replace the motor.Yes/NoNONOChecksIs the duplexing inlet sensor(PS15) normal?Does the set-back roller rotateclockwise and counterclockwise atspecific timing?Step12RemedyReplace the faultysensor.Replace the motor.Yes/NoNONOChecksAre the following sensors normal?• duplexing outlet paper sensor(PS14)• duplexing horizontal registrationpaper sensor (PS17)• duplexing pre-registration papersensor (PS18)Does the set-back roller rotateclockwise and counterclockwise atspecific timing?Step125 Duplexing Unit (during re-pick up operation)CauseSensorSet-back motor(M5)

Canon NP6621 Service Handbook

I. FEATURES

II. SPECIFICATIONS

Cassette Feeding Module-A2/Cassette Feeding Unit-K1

C. Paper Deck Pedestal-K1

III. NAMES OF PARTS

B. Cross Section

IV. BASIC OPERATION

B. Making Copies

C. Using the Stack Bypass

D. User Mode

auto clear time

initializing user mode

V. WARNINGS AND ACTIONS

B. Cleaning the Static Charge Eliminator

VI. ROUTINE CLEANING

CHAPTER 2 COPYING PROCESS

I. IMAGE FORMATION

B. Latent Static Image Formation Block

C. Step 1 (pre-exposure)

E. Step 3 (image exposure)

G. Step 5 (transfer)

H. Step 6 (separation)

I. Step 7 (fixing)

II. AUXILIARY PROCESS

CHAPTER 3 OPERATIONS AND TIMING

I. BASIC OPERATIONS

B. Outline of Electrical Circuitry

C. Inputs to the DC Controller

D. Outputs from the DC Controller

E. Inputs to and Outputs from the Cassette Feeding Module-B2 Driver PCB

F. Inputs to and Outputs from the Cassette Feeding Module-A2 Driver PCB

G. Inputs to and Outputs from the Cassette Feeding Unit-K1 Driver PCB

H. Main Motor Control Circuit

II. EXPOSURE SYSTEM

lens motor drive circuit

C. Scanner Drive System

driving the scanner motor

D. Operations of the Scanner in Page Separation Mode

j. blank exposure control

a. pick-up from the machine

C. Duplexing Unit

D. Pick-Up from the Cassette Feeding Module-A2

E. Pick-Up from the Cassette Feeding Unit-K1

F. Paper Deck Pedestal-K1

lifter operation

G. Multifeeder

H. Identifying the Size of the Cassette

I. Fixing/Delivery Assembly

J. Detecting Jams

delivery delay jam

delivery stationary jam

V. POWER SUPPLY

B. Power Supply Circuitry

C. Detecting Errors on the Power Supply PCB

D. Protection Mechanisms for the Power Supply Circuit

VI. SERVICE MODE

C. Control Display Mode ('1')

D. I/O Mode ('2')

E. Adjustment Mode ('3')

F. Operation/Inspection Mode ('4')

G. Machine Settings Mode ('5')

H. Counter Mode ('6')

VII. SELF DIAGNOSIS

B. Self Diagnosis on the Cassette Feeding Unit

C. RDF/ADF Self Diagnosis

D. Sorter Self Diagnosis

VIII. STANDARDS AND ADJUSTMENTS

checking the photointerrupters

CHAPTER 4 MECHANICAL SYSTEM

I. EXTERNALS

B. Control Panel

removing the exhaust fan

E. Counter

II. DRIVE SYSTEM

routing the scanner cable

B. Lens Drive Assembly

routing the lens cable

C. Main Motor

III. PICK-UP/FEEDING SYSTEM

removing the separation pad

B. Multifeeder Assembly

C. Registration Roller Assembly

D. Feeding Assembly

F. Duplexing Assembly

G. Cassette Unit

H. Paper Deck Pedestal-K1

points to note

removing the separation roller

IV. EXPOSURE SYSTEM

routing the blank shutter cable

V. CHARGING SYSTEM

B. Primary Charging Assembly

NP6621

GENERAL CIRCUIT DIAGRAM

feeding unit-k

basic construction

g. multifeeder

j. detecting jams

v. power supply

b. power supply circuitry

power supply pcb

vi. service mode

a. copier self diagnosis

c. rdf/adf self diagnosis

d. sorter self diagnosis

a. electrical

b. control panel

d. fan

e. counter

ii. drive system

b. lens drive assembly

c. main motor

b. multifeeder assembly

d. feeding assembly

f. duplexing assembly

g. cassette unit

h. paper deck pedestal-k

iv. exposure system

v. charging system

d. drum heater

vii. fixing system

a. dc controller pcb

c. ae sensor pcb

A. Unpacking and Removing Fixings

b. turning on the copier

d. attaching the drum unit

e. changing the cassette size

iii. relocating the copier

iv. replacing the drum unit

vi. cassette heater kit 5 installation

b. installation

B. Installation to the Copier

K. CASSETTE FEEDING MODULE-B2 DRIVER CIRCUIT DIAGRAM

circuit diagram