Xerox DocuPrint C55 User manual

Color Laser Printer
(50/60 Hz)
Service Manual
701P14760
February, 1999
CAUTION
Certain components in the DocuPrint C55/C55mp/
[NC60] Color Laser Printers are susceptible to
damage from electrostatic discharge. Observe all
ESD procedures to avoid component damage.
DocuPrint C55/C55mp/[NC60]

NOTICE
“All Service documentation is supplied to Xerox
external customers for informational purposes
only. Xerox Service Documentation is intended
for use by certified, product trained personnel
only. Xerox does not warrant or represent that
such documentation is complete, nor does Xerox
represent or warrant that it will notify or provide
to such customer any future changes to this
documentation. Customer performed service of
equipment, or modules, may affect the warranty
offered by Xerox with respect to such equipment.
You should consult the applicable warranty for its
terms regarding customer or third party provided
service. If the customer services such
equipment, modules, components or parts
thereof, the customer releases Xerox from any
and all liability for the customer actions, and the
customer agrees to indemnify, defend and hold
Xerox harmless from any third party claims
which arise directly or indirectly from such
service.”
Prepared by:
Xerox Corporation
Multinational Customer and Service Education
780 Salt Road
Webster, New York 14580
©1999 by Xerox Corporation. All rights reserved.
Xerox and all Xerox products mentioned in this publication
are registered trademarks of the Xerox Corporation
CLASS 1 LASER PRODUCTS
This product is certified as a Class 1 Laser
product and complies with DHHS Laser-
Radiation Standards, 21 CFR Chapter 1 Sub-
chapter J. WARNING
Use of controls, adjustments, or perform-
ances of procedures other than those
specified in this manual may result in
hazardous radiation exposures.
The C55/C55mp/[NC60] each contain an
invisible laser. There is no visual indication that
the laser beam is present. During servicing, the
C55/C55mp/[NC60] remain a Class 1 product
because of the interlock system. Do not attempt
to cheat the interlock switches on this printer.

Product
DocuPrint C55/C55mp/[NC60] Title Service Manual Part Number 701P14760 Date February 1999
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TABLE OF CONTENTS
2/99
DocuPrint C55/C55mp/[NC60] i
TABLE OF CONTENTS
TITLE PAGE
INTRODUCTION
About This Manual --------------------------------- ii
Organization ----------------------------------------- ii
How to use This Manual--------------------------iii
Reference Symbology-----------------------------iii
SERVICE CALL PROCEDURES
Contents------------------------------------------- 1-1
STATUS INDICATOR RAPS
Contents------------------------------------------- 2-1
IMAGE QUALITY RAPS
Contents------------------------------------------- 3-1
REPAIR/ADJUSTMENT PROCEDURES
Contents------------------------------------------- 4-1
PARTS LIST SECTION
Contents------------------------------------------- 5-1
GENERAL PROCEDURES/INFORMATION
Contents------------------------------------------- 6-1
WIRING DATA
Contents------------------------------------------- 7-1

INTRODUCTION
2/99
INTRODUCTION
ii DocuPrint C55/C55mp/[NC60]
ABOUT THIS MANUAL
This manual is part of a multinational
documentation system which includes
Training.
This manual contains information that applies
to:
•USCO
•XE
•XCL
•ACO
This service manual covers both the C55 and
NC60 product families.
Unique NC60 directions will be given in [ ]s.
For example:
Press the On Line [0] key.
The On Line key is unique to the C55 family
and the [0] key is unique to the NC60.
If the entire procedure is unique to a product
family, it will be noted at the top of the page
and in the footer at the bottom of the page.
“USCO” references apply to 115 Volt printers.
“XE” references apply to 220/240 Volt printers.
“Dry Ink” means the same as “Toner” and
“Tag” means the same as “Mod”.
ORGANIZATION
This manual is divided into seven sections
organized as follows:
A Publications comment sheet is provided at
the end of this manual.
Section 1 - SERVICE CALL PROCEDURES
This section contains the following:
•Call Flow Instructions
•Initial Actions
•System Checks
•Every Call Activities
•Scheduled Maintenance
•Final Action
Call Flow
The call flow chart shows you how to conduct
the service call.
Initial Actions
The initial actions suggests how to collect data
necessary to proceed with the service call.
System Checks
The System Checks procedures details the
steps for effective repair and verification of
repair of problems found in Initial Action.
Every Call Activities
These are cleaning and maintenance activities
which are performed on every call.
Scheduled Maintenance
Scheduled Maintenance consists of checking
the life remaining on the CRUs.
Final Action
Final Action ensures that image quality is
acceptable, and that printer performance and
appearance is satisfactory. Details are
included for completing administrative tasks
and closing out the service call.
Section 2 - STATUS INDICATOR REPAIR
ANALYSIS PROCEDURES (RAPs)
This section contains the Repair Analysis
Procedures (RAPs) necessary to repair faults
other than image quality faults.
Section 3 - IMAGE QUALITY REPAIR
ANALYSIS PROCEDURES (RAPs)
This section contains the Repair Analysis
Procedures (RAPs) necessary to repair image
quality faults.
Section 4 - REPAIR/ADJUSTMENT
PROCEDURES
This section contains the Repair and
Adjustment procedures for the printer. All
unique procedures will be identified as follows:
•USCO
•XE
Section 5 - PARTS LIST
This section contains exploded view drawings
and referenced replaceable parts lists for the
Printer.
Section 6 - GENERAL PROCEDURES
This section contains Diagnostic procedures,
Menus, Product Specifications, ESS/IOT test
patterns, and other General Procedures.
Section 7 - WIRING DATA
This section contains Block Schematic
Diagrams (BSDs), Plug/Jack/PWB Location
Diagrams and wiring diagrams.

2/99
DocuPrint C55/C55mp/[NC60] iii
INTRODUCTION
HOW TO USE THIS MANUAL
Section 1, Service Call Procedures will direct
you to each section of the manual necessary
to perform a service call.
You will begin with Initial Actions which
suggest how to collect problem symptoms and
evidence to be used in the next section, the
System Checks Section.
Details in the System Checks are designed to
assist you in classifying, repairing and verifying
the repair of the problem. From here, you may
be directed to any of the other six sections of
the service manual depending on the
symptoms observed and the results of
suggested tests. After a repair has been
verified (or during a repair activity) instructions
are included to direct you into Every Call
Activities.
REFERENCE SYMBOLOGY
Reference Symbology provides supportive
data for Repairs, Adjustments, and the RAPs.
The symbols that refer to this supportive data
are shown in the paragraphs that follow.
Note: This symbol is used to refer to notes,
usually found on the same page.
Parts Lists
PL 2.4 (example)
In the example above, the parts list reference
and the exploded view drawing would be found
in Section 5 on sub-section 2.4.
Descriptions of commonly used graphic
symbols are included in order to aid
troubleshooting when using the circuit
diagrams.
Switches/Relays
Safety interlock switch, circuit open.
Safety interlock switch, circuit closed.
Switch/relay with momentary contacts
shown normally open.
Switch/relay with momentary contacts
shown normally closed.
Magnetically actuated Switch.
Miscellaneous Symbols
A flag that identifies a wire that has
been referred to in the text.
[ 8-2 ] Indicates a Diagnostic Code used to
check a particular component.
Identifies a test point, test hole or test
stake on a PWB.
Auditron/Key Counter connection.
This symbol, used with a number,
indicates that the actual number may
be equal to or very near the value of
the designated number.
Triac, used to switch AC power.
Light Emitting Diode (LED).
Led/Phototransistor Sensor.
Motor.
Thermistor Bead, used to sense
temperature.
A Driver which is used to switch on
DC Components.
Analog to Digital Converter.
Relay
Solenoid
12
A
MOT
GND
A/D
RL

2/99
INTRODUCTION
iv DocuPrint C55/C55mp/[NC60]
Signal Continuation/Flow
Indicates the continuation of a signal
line interrupted in a horizontal
direction.
Represents the continuation of a
standby power line interrupted in the
vertical direction. In all cases, the
supply is from Standby Power
Indicates a feedback signal.
Indicates a common splice of wires.
Indicates a common splice of wires at
a pin.
Indicates the direction of signal flow.
Indicates that the wire continues to
the adjacent page.
Tag Identification
This WITH TAG Symbol is used to
identify the components or configura-
tion that are part of a printer change
covered by the Tag number.
This WITHOUT TAG Symbol is used
to identify the components or
configuration that are not part of a
printer change covered by the Tag
number
6
P/J57
47
47
47
47

1. SERVICE CALL PROCEDURES
2/99 SERVICE CALL PROCEDURES
DocuPrint C55/C55mp/[NC60] 1-1SECTION CONTENTS
TITLE PAGE
CALL FLOW---------------------------------------1-2
INITIAL ACTION ---------------------------------1-3
SYSTEM CHECKS ------------------------------1-3
EVERY CALL ACTIVITIES --------------------1-4
SCHEDULED MAINTENANCE---------------1-4
FINAL ACTION-----------------------------------1-5

SERVICE CALL PROCEDURES 2/99
CALL FLOW 1-2DocuPrint C55/C55mp/[NC60]
CALL FLOW
SYSTEM CHECKS
This step is used to suggest a direction for using the
information, obtained during Initial Action. You can
then repair and verify the repair of the problem. This
step may also provide information to assist in the
identification of new problems and suggest actions to
take to repair/resolve them.
FINAL ACTIONS
This step is used to ensure that the print quality, the
printer performance, and the printer appearance is
satisfactory. It will also provide direction to help
complete administrative tasks.
INITIAL ACTION
This step is used to gather information about the
reason for the call, to determine the machine
condition, and to run print samples.
EVERY CALL ACTIVITIES
This step consists of every call cleaning and
maintenance activities.
SCHEDULED MAINTENANCE
This step is used to check the life remaining on the
CRU’s.

2/99 SERVICE CALL PROCEDURES
DocuPrint C55/C55mp/[NC60] 1-3INITIAL ACTION/SYSTEM CHECKS
INITIAL ACTION
Purpose
To suggest how to gather information about
the service call, the machine condition, and to
direct the user through the call.
PROCEDURE
1. Ask the customer to describe the problem
that causes the service call and the job
being run when the problem occurred.
2. Inspect any rejected prints for evidence of
defects.
3. Switch the printer power Off/On and check
for and note/record any fault codes in the
Control Panel Display.
4. Examine the Machine Service Log (under
the Left Side Cover) for previous problems
or activities that may be related to this
service call.
5. Go to (SYSTEM CHECKS).
SYSTEM CHECKS
Purpose
To suggest a direction for effective repair and
verification of repair of problems found in Initial
Action.
PROCEDURE
1. Select the appropriate situation from a-g
below, then diagnose and repair the
problem.
a. Replace any obviously broken parts.
b. If this is an Image Quality problem, go
to IQ1 Image Quality Entry RAP in
Section 3.
c. If there is a Fault Code, go to Section
2 Table of Contents. Locate and
perform the RAP associated with the
Fault Code.
d. If there is NO fault code associated
with the problem, go to Section 2
Table of Contents. Locate and
perform the RAP which most closely
matches the problem described by the
customer.
e. If the problem is not repeatable,
operate the printer in the same job
conditions the customer used and
recheck for a problem in the
categories listed here.
f. If the problem still is not reproduced,
check the printer Fault History.
(C55/C55mp)
Off Line, Menu, then scroll to
<SERVICE>, <ERROR LOGS>,
<FAULT HISTORY>. Scroll through
the Fault History and note any
repeating faults. Refer to the RAP for
these fault codes in Section 2 and
read the fault code description to see
if the code relates to the customer
problem. If so, perform the RAP
[NC60]
Menu Up until Print Menu. Item Up
until Fault History then press Enter.
Look through the Fault History and
note any repeating faults. Refer to the
RAP for these fault codes in Section 2
and read the fault code description to
see if the code relates to the customer
problem. If so, perform the RAP.
g. If none of the above situations applies
go to EVERY CALL ACTIVITIES.
2. Verify that the problem is corrected and go
to EVERY CALL ACTIVITIES.

SERVICE CALL PROCEDURES
EVERY CALL ACTIVITIES/ 2/99
SCHEDULED MAINTENANCE 1-4DocuPrint C55/C55mp/[NC60]
EVERY CALL ACTIVITIES
Purpose
To list service activities required for specific
subsystems.
PROCEDURE
1. Open the printer and Clean the Charge
Scorotron using the Scorotron cleaner.
2. Clean the toner loading area.
3. Remove the Following:
a. Print Drum Module. (GP I)
b. Color Developer Module. (GP 2)
c. Black Developer Module (GP 3)
d. Toner Collector. (GP 4)
4. Vacuum the Drum, Developer, and Toner
Collector areas.
5. Replace the Toner Collector if required.
6. Reinstall the following:
a. Black Developer Module (GP 3)
b. Color Developer Module. (GP 2)
c. Print Drum Module. (GP I)
d. Toner Collector. (GP 4)
7. Use Film Remover to clean the Feed
Rollers. Do not rotate the Feed Rollers
more than 270° while cleaning. Apply
Rubber restore if available.
8. Check the Transfer Drum Nip Adjustment
(ADJ 11.1)
9. Wipe the outside of the printer.
SCHEDULED MAINTENANCE
Purpose
To check the life remaining on the CRUs.
PROCEDURE
1. Check the life of the Customer Replace-
able Units (CRUs).
a. (C55/C55mp)
Enter the Off Line mode, press Menu
and scroll to <MAINTENANCE>.
[NC60]
Menu Up until Service Menu, Item Up
until CRU Usage, Value Up to see %
remaining on the CRUs.
b. Check the life remaining on the
following:
•Black Developer Cartridge.
•Color Developer Cartridge.
•Print Drum.
•Fuser Module.
2. If any of the CRUs are near end of life,
notify the customer.

2/99 SERVICE CALL PROCEDURES
DocuPrint C55/C55mp/[NC60] 1-5FINAL ACTION
FINAL ACTION
Purpose
To ensure the image quality is acceptable,
printer performance and appearance is
satisfactory and to complete administrative
tasks.
PROCEDURE
1. Install/close all covers and doors.
2. Run the Print Quality sample set.
a. (C55/C55mp)
Enter the Off Line mode, press Menu
and scroll to <SERVICE>. Select
<TEST PATTERNS>, and print the
PQ set.
[NC60]
Menu Up until Service Menu, Item
Down until Print PQ Set and press
Enter.
3. If possible, ask the customer to print one
of their representative prints to examine
and comment on.
Wrap-Up Procedure
1. Record your service activities in the
service log.
2. Record the Total meter reading (from the
Diagnostic Test Pattern) in the service log.
3. Record the ESS software level (from the
Diagnostic Test Pattern) in the service log.
4. (C55/C55mp)
(Off Line, Print, Settings). Record the NIC
software level (from the Settings page) in
the service log.
5. Put the Printer PQ set and service log into
the service log folder.
NOTE: It is very important to save the PQ
set. There is information on the Diagnostic
sheet (Toner Concentration setpoints) which
will be needed if the NVM is reset or the PCU
PWB is replaced.

SERVICE CALL PROCEDURES 2/99
NOTES 1-6DocuPrint C55/C55mp/[NC60]
Notes:

2. STATUS INDICATOR RAPs
2/99 STATUS INDICATOR RAPs
DocuPrint C55/C55mp/[NC60] 2-1SECTION CONTENTS
TITLE PAGE
TROUBLESHOOTING TIPS ------------------2-2
C1-CHECK TRAY 1 -----------------------------2-3
C2-CHECK TRAY 2 -----------------------------2-3
E1-TRAY 1 JAM----------------------------------2-4
E2-TRAY 2 JAM ---------------------------------2-5
E3-BYPASS JAM --------------------------------2-5
E4-INPUT JAM -----------------------------------2-6
E5 FUSER JAM ----------------------------------2-7
E6-DRUM JAM -----------------------------------2-8
E7-PRINT DRUM JAM------------------------2-10
E8-OUTPUT JAM------------------------------2-10
E9-CLOSE PRINTER-------------------------2-10
EA-COLOR DEV. MISINSTALLED--------2-11
EB-BLACK DEV. MISINSTALLED---------2-11
EC-PRINT DRUM MISINSTALLED--------2-11
F1-DISK ERROR (FLOPPY) ----------------2-12
F2-DISK I/O ERROR (FLOPPY) -----------2-12
F3-ACTION FAILED (FLOPPY) ------------2-12
H1-HARD DISK ERROR---------------------2-13
H2-HARD DISK CONTROLLER
ERROR -------------------------------------2-13
H3-HARD DISK FULL-------------------------2-14
H4-FORMAT HARD DRIVE-----------------2-14
TITLE PAGE
J1-ADD YELLOW TONER-------------------2-15
J2-ADD MAGENTA TONER ----------------2-16
J3-ADD CYAN TONER-----------------------2-17
J4-ADD BLACK TONER ---------------------2-18
J5-REPLACE COLOR DEVELOPER
CARTRIDGE--------------------------------2-19
J6-REPLACE BLACK DEVELOPER
CARTRIDGE--------------------------------2-19
J7-TONER COLLECTOR FULL------------2-20
J8-REPLACE PRINT DRUM----------------2-20
J9-REPLACE FUSER MODULE -----------2-20
JA-REPLACE OIL/PAD-----------------------2-21
T0-FUSER THERMISTOR ERROR-------2-21
T1- UNDER TEMPERATURE --------------2-22
T2- OVER TEMPERATURE ----------------2-23
U0-IOT ROM ERROR ------------------------2-23
U1-IOT RAM ERROR-------------------------2-24
U2-IOT NVM RAM ERROR -----------------2-24
U3-IOT/ESS COMMUNICATION
ERROR -------------------------------------2-24
U4-OPTICS FAULT ---------------------------2-25
U5-POLYGON MOTOR FAULT------------2-25
U6-MOTOR FAULT (DEVELOPER) ------2-26
U7- MOTOR FAULT (MAIN) ----------------2-27
TITLE PAGE
W1-COLOR DEVELOPER MODULE
(NEAR END OF USE)-------------------2-28
W2-BLACK DEVELOPER MODULE
(NEAR END OF USE)-------------------2-28
W3-PRINT DRUM (NEAR
END OF USE)-----------------------------2-28
W4-FUSER MODULE
(NEAR END OF USE)-------------------2-29
W5-FUSER OIL BOTTLE/PAD
(NEAR END OF USE)-------------------2-29
OF1 DEAD PRINTER RAP ----------------2-30
OF2 CONTROL PANEL RAP -------------2-32
OF3 TRAY 1 PAPER SIZE
SENSING RAP-------------------------2-35
OF4 TRAY 2 PAPER SIZE
SENSING RAP-------------------------2-36
OF5 LOAD PAPER RAP--------------------2-37
OF6AESS RAP (C55/C55mp)--------------2-38
OF6BESS RAP [NC60]-----------------------2-39
OF7 ESS BOOT FAILURE
ERROR CODES [NC60] -------------2-40
OF8 ARCING RAP---------------------------2-41

STATUS INDICATOR RAPs 2/99
TROUBLESHOOTING TIPS 2-2DocuPrint C55/C55mp/[NC60]
TROUBLESHOOTING TIPS
The following are some general trouble-
shooting tips and hints which will help you
locate components and test points.
1. The procedures for entering, exiting and
using the C55/C55mp/[NC60] diagnostic
programs can be found in Section 6,
General Procedures. Refer to the Table of
Contents found on page 6-1 for the
specific program.
2. Figure 2-1 on the right is also located in
Section 6 and shows the location of the
input electrical components in the printer.
It is especially helpful when using the
Switch Scan program. Refer to this figure
if you are unsure of input component
location. The BSDs in Section 7 may also
prove helpful when locating the various
electrical components.
3. The Connectors can be located in
Section 7. Refer to Section 7 Table of
contents on page 7-1. The table below
shows the location of the most common
connectors:
Connector
Numbers Location Figure
CN100’sPCU PWB/ESS PWB 7-1
CN200’sCassette PWB 7-4
CN300’sConnector PWB 7-2
CN400’sControl Panel PWB 7-2
CN700’sLVPS PWB 7-2
CN800’sHVPS PWB 7-3
+24 V
INTERLOCK
SWITCH
EXIT SENSOR
GAMMA
SENSOR
TRANSFER DRUM
HOME SENSOR
PHOTORECEPTOR
DETECT
PS0 PS1 PS2 PS3 PS4
TRAY EMPTY
SENSOR
REGISTRATION
SENSOR
T2
S0
WASTE TONER
BOTTLE SENSOR
BYPASS SWITCH
TRANSPARENCY
SENSOR
T2 TRAY EMPTY
SENSOR T2
S1 T2 S3 T2
S4
OIL
SENSOR
TRANSPARENCY
JAM SENSOR
CLEANER JAM
SWITCH
T2
S2
TEMPERATURE/
HUMIDITY SENSOR
Figure 2-1. Input Component Location

2/99 STATUS INDICATOR RAPs
DocuPrint C55/C55mp/[NC60] 2-3C1, C2
C1 CHECK TRAY 1 RAP
Cassette 1 is not in the printer.
INITIAL ACTION
Load paper and insert Cassette 1 into the
printer.
Switch the power off wait 10 seconds and
switch the power on. Recheck for the fault.
PROCEDURE
Enter IOT normal diagnostics. Scroll to the
SWITCH SCAN program and select Scan Row
01, Press Form Feed [1].
Remove Cassette 1. Manually make and
break Paper Size Sensor 0 while observing the
Cyan LED. (Sensor 0 is the first one on the
left when viewed from the front of the printer.)
The Cyan LED switches on and off.
YN
Go to BSD 7.2 in Section 7 and trouble-
shoot the Paper Size 0 Sensor signal
(CN107-8) for a short to ground.
If no short is found, replace the PCU
PWB. If the problem still exists, replace
the Cassette PWB.
Check for a broken Sensor Flag on the Tray 1
Cassette.
If the problem still exists, replace the PCU
PWB. If the problem still exists, replace the
Cassette PWB.
C2 CHECK TRAY 2 RAP
Cassette 2 is not in the printer.
INITIAL ACTION
Move the length stop to the 11 inch position
(Figure 2-2), load paper, and insert Cassette 2
into the printer.
Switch the power off wait 10 seconds and
switch the power on. Recheck for the fault.
PROCEDURE
Enter IOT normal diagnostics. Scroll to the
SWITCH SCAN program and select Scan Row
03. Press Form Feed [1].
Remove Cassette 2. Manually make and
break T2 Paper Size Sensor 0 while observing
the Cyan LED.
The Cyan LED switches on and off.
YN
Refer to BSD T2, 7.2 in Section 7 and
check the following:
•T2 Paper Size 0 Sensor signal CN109-
1 for an open.
•+5 VDC CN109-5
If no problem is found, replace the PCU
PWB. If the problem still exists, replace
the T2 Cassette PWB.
Check for a broken Sensor Flag on the Tray 2
Cassette.
If the problem still exists, replace the PCU
PWB. If the problem still exists, replace the
Cassette PWB.
14"10.5" 11", A4
Figure 2-2. Length Stop Location

STATUS INDICATOR RAPs 2/99
E1 2-4DocuPrint C55/C55mp/[NC60]
E1 TRAY 1 JAM RAP
Paper fed from Tray 1 did not reach the
Registration Sensor.
INITIAL ACTION
Remove the cassette and check that the paper
is loaded correctly and is in good condition.
Switch the power off wait 10 seconds and
switch the power on. Recheck for the fault.
PROCEDURE
Check the following:
•Obstructions in the paper path.
•Dirty Feed Rolls.
•Dirty Drive Rollers.
•Mechanical drive problem.
Enter IOT normal diagnostics. Scroll to the
SWITCH SCAN program and select Scan Row
00. Press Form Feed [1].
Open the Printer. Actuate and deactuate the
Registration Sensor while observing the
Magenta LED.
The Magenta LED switches on and off.
YN
Go to BSD 8.1 in Section 7 and trouble-
shoot the Registration Sensor signal, +5
VDC and GND (CN102-9, 7, 8) for an
open.
If no open exists, replace the PCU PWB.
If the problem still exists, replace the
Registration Sensor.
Press Media Server [2]. Select Scan Row 01.
Press Form Feed [1].
Remove the cassette and actuate and
deactuate the Tray Empty Sensor while
observing the Black LED.
A
A
The Black LED switches on and off.
YN
Go to BSD 7.1 in Section 7 and trouble-
shoot the Tray Empty Sensor signal
(CN102-6) for a short to ground.
If no short exists, replace the PCU PWB. If
the problem still exists, replace the Tray
Empty Sensor.
Exit from the SWITCH SCAN program.
Close the Printer.
Remove the paper cassette. Scroll to the
MOTOR TEST program. Press Form Feed
[1] to switch on the motors while observing the
Paper Feed Motor.
The Paper Feed Motor is rotating normally.
YN
Go to BSD 7.3 in Section 7 and trouble-
shoot the +24 VDC Interlocked (CN111-5)
and Paper Feed Motor for an open. If the
motor was noisy, check the clock lines.
If the lines are OK, replace the PCU PWB.
If the problem still exists, replace the
Paper Feed Motor.
Exit from diagnostics.
Set up the meter to read +24 VDC. Measure
between CN101-5 (+) and ground (−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0.
YN
Go to BSD 7.4 in Section 7 and trouble-
shoot the Feed Solenoid signal, and +24
VDC Interlocked (CN101-5, 3) for an
open.
B C
B C
If no open exists, replace the PCU PWB. If
the problem still exists, replace the Paper
Feed Solenoid.
Check for a mechanical problem with the feed
clutch.

2/99 STATUS INDICATOR RAPs
DocuPrint C55/C55mp/[NC60] 2-5E2, E3
E2 TRAY 2 JAM RAP
Paper fed from Tray 2 did not reach the
Registration Sensor.
INITIAL ACTION
Remove the cassette and check that the paper
is loaded correctly and is in good condition.
Check the position of the rear stop.
Make sure that Tray 1 is pushed all the way in.
Switch the power off wait 10 seconds and
switch the power on. Recheck for the fault.
PROCEDURE
Try to run a print from Tray 1.
The print feeds OK from Tray 1.
YN
Go to E1 TRAY 1 JAM RAP.
Check the following:
•Obstructions in the paper path.
•Dirty Feed Rolls.
•Dirty Drive Rollers.
•Mechanical drive problem.
Enter IOT normal diagnostics. Scroll to the
SWITCH SCAN program and select Scan Row
03. Press Form Feed [1].
Remove cassette 2. Actuate and deactuate
the Tray 2 Empty Sensor while observing the
Black LED.
The Black LED switches on and off.
YN
Go to BSD T2 7.1 in Section 7 and
troubleshoot the T2 Tray Empty Sensor
signal (CN109-4) for a short to ground.
If no short exists, replace the PCU PWB.
If the problem still exists, replace the Tray
2 Empty Sensor.
A
A
Exit from diagnostics.
Set up the meter to read +24 VDC. Measure
between CN109-8 (+) and ground (−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0 and
back to +24.
YN
Go to BSD T2 7.3 in Section 7 and
troubleshoot the T2 Feed Solenoid signal,
and +24 VDC Interlocked (CN109-8, 7) for
an open.
If no open exists, replace the PCU PWB. If
the problem still exists, replace the T2
Feed Solenoid.
Measure between CN109-9 (+) and ground
(−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0 and
back to +24.
YN
Go to BSD T2 7.4 in Section 7 and
troubleshoot the T2 Drive Clutch signal
(CN109-9) for an open.
If no open exists, replace the PCU PWB.
If the problem still exists, replace the T2
Drive Clutch.
Check for a mechanical problem with the Feed
Clutch and Drive Clutch
E3 BYPASS JAM RAP
Paper fed from the Bypass Tray did not reach
the Registration Sensor.
INITIAL ACTION
Carefully inspect the bypass opening for
paper.
Switch the power off wait 10 seconds and
switch the power on. Run another print and
recheck for the fault.
PROCEDURE
If paper does not feed from the Bypass but
does feed from Tray 1, check for an
obstruction in the bypass slot.
Check to ensure that the switch is installed
correctly and has not fallen out.
If no paper is loaded in the Bypass when the
E3 occurs, refer to BSD 7.5 in Section 7 and
check the Bypass Switch signal (CN312-2) for
a short to ground.
If no short exists, replace the PCU PWB. If
the problem still exists, replace the Bypass
Switch.

STATUS INDICATOR RAPs 2/99
E4 2-6DocuPrint C55/C55mp/[NC60]
E4 INPUT JAM RAP
Paper was on the Registration Sensor too
long.
INITIAL ACTION
Open the printer and check for any obstruction
in the register roller area.
Switch the power off wait 10 seconds and
switch the power on. Run another print to
recheck for the fault.
Make sure the Grounding Roller is rotating
freely.
Perform the Transfer Drum Nip Adjustment
(ADJ 11.1)
PROCEDURE
Enter IOT normal diagnostics. Scroll to the
SWITCH SCAN program and select Scan Row
00. Press Form Feed [1].
Open the Printer. Actuate and deactuate the
Registration Sensor while observing the
Magenta LED.
The Magenta LED switches on and off.
YN
Go to BSD 8.1 in Section 7 and trouble-
shoot the Registration Sensor signal
(CN102-9) for a short to ground.
If no short exists, replace the PCU PWB.
If the problem still exists, replace the
Registration Sensor.
Press Media Server [2]. Select Scan Row 04.
Press Form Feed [1].
Actuate and deactuate the Transparency
Sensor while observing the Cyan LED.
A
A
The Cyan LED switches on and off.
YN
Go to BSD 8.4 in Section 7 and trouble-
shoot the Transparency Sensor signal
(CN311-1) for a short to ground.
If no short exists, replace the PCU PWB.
If the problem still exists, replace the
Transparency Sensor.
Exit from the SWITCH SCAN program.
Close the Printer.
Remove the paper cassette. Scroll to the
MOTOR TEST program and press Form Feed
[1] to switch on the motors while observing the
Paper Feed Motor.
The Paper Feed Motor is rotating normally.
YN
Go to BSD 7.3 in Section 7 and trouble-
shoot the Paper Feed Motor clock lines.
If the lines are OK, replace the PCU PWB.
If the problem still exists, replace the
Paper Feed Motor.
Exit from diagnostics.
Set up the meter to read +24 VDC. Measure
between CN103-4 (+) and ground (−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0 and
back to +24.
YN
Go to BSD 9.16 in Section 7 and trouble-
shoot the Stripper Solenoid signal and +24
VDC Interlocked (CN103-4, CN303-2,1) for
an open.
If no open exists, replace the PCU PWB. If
the problem still exists, replace the
Stripper Solenoid.
B
B
Set up the meter to read +24 VDC. Measure
between CN101-5 (+) and ground (−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0 and
back to +24.
YN
Go to BSD 7.4 in Section 7 and trouble-
shoot the Feed Solenoid signal (CN101-5)
for a short to ground.
If no short exists, replace the PCU PWB.
If the problem still exists, replace the Feed
Solenoid.
Set up the meter to read +24 VDC. Measure
between CN101-4 (+) and ground (−).
Make one print while monitoring the meter.
The meter swings from +24 VDC to 0 and
back to +24.
YN
Go to BSD 8.2 in Section 7 and trouble-
shoot the Registration Clutch signal and
+24 VDC Interlocked (CN101-4, 1) for an
open.
If no open exists, replace the PCU PWB. If
the problem still exists, replace the
Registration Clutch.
Check the following:
•Obstructions torn paper etc. in the paper
path.
•Mechanical drive problem.