NCR 7194 Service Manual

NCR 7194 Thermal Receipt
Printer

Release 1.0

Service Guide

B005-0000-1098
Issue D

The product described in this book is a licensed product of NCR Corporation.
NCR is a registered trademark of NCR Corporation.
It is the policy of NCR Corporation (NCR) to improve products as new technology, components, software,

and firmware become available. NCR, therefore, reserves the right to change specifications without prior
notice.

All features, functions, and operations described herein may not be marketed by NCR in all parts of the
world. In some instances, photographs are of equipment prototypes. Therefore, before using this document,
consult with your NCR representative or NCR office for information that is applicable and current.

To maintain the quality of our publications, we need your comments on the accuracy, clarity, organization,
and value of this book.

Address correspondence to:
Manager, Information Products

NCR Corporation
2651 Satellite Blvd.
Duluth, GA 30096

Copyright © 1999
By NCR Corporation
Dayton, Ohio U.S.A.
All Rights Reserved

Service Guide i

Preface

Important Information to the User

In order to ensure compliance with the Product Safety, FCC and CE
marking requirements, you must use the power supply, power cord,
and interface cable, which were shipped with this product or which
meet the following parameters:

Power Supply

UL Listed (QQGQ), Class 2 power supply with SELV (Secondary Extra
Low Voltage), non-energy hazard output, limited energy source, input
rated 100-240 Vac, 1.5/0.8 A, 50/60 Hz, output rated 24 Vdc, 2.3 A.

Use of this product with a power supply other than the NCR power
supply will require you to test this power supply and NCR printer for
FCC and CE mark certification.

Interface Cable

A shielded (360 degree) interface cable must be used with this product.
The shield must be connected to the frame or earth ground connection
or earth ground reference at EACH end of the cable.

Use of a cable other than described here will require that you test this
cable with the NCR printer and your system for FCC and CE mark
certification.

Power Cord

A UL listed, detachable power cord must be used for this product. For
applications where the power supply module may be mounted on the
floor, a power cord with Type SJT marking must be used. For
applications outside the US, power cords, which meet the particular
country’s certification and application requirements, should be used.

Use of a power cord other than described here may result in a violation
of safety certifications, which are in force in the country of use.

ii Service Guide

How to Use This Book

Use this book as a training guide for teaching users how to operate the
printer or as a reference for programming the host computer to
communicate with the printer. In addition, information is also
provided about the character sets and graphics that are available. The
book is divided into chapters that relate to each of these areas.

See the Contents, or Index for detailed listings.

Who Should Use This Book?

This book is intended as a general guide for operators and supervisors
who need to know how to use the printer. It is also intended as a
technical guide for programmers and system integrators who need to
know the technical information about the printer's communication and
the programming commands used by the host computer to control the
functions of the printer.

How to Obtain More Information

For more information about the 7194 printer and to order the following
documentation, please contact your NCR supplier:

•

7194 Thermal Receipt Printer: Owner’s Guide

(B005-0000-1097)
Service and disassembly procedures (you must be a trained service
representative to service the printer)

Service Guide iii

Table of Contents

Chapter 1:

Technical Specifications

Reliability ...............................................................................................1-1

Power Requirements.............................................................................1-2

Environmental Conditions ..................................................................1-3

Dimensions and Weight.......................................................................1-4

Printing Specifications..........................................................................1-5

Density of Receipt Print Lines.............................................................1-6

Duty Cycle Restrictions (Printing Solid Blocks) ...............................1-7

Allowable Duty Cycle (measured over one minute of

continuous printing) ......................................................................1-8

Chapter 2:

Diagnostics and Configurat ion

Startup Diagnostics...............................................................................2-2

Runtime Diagnostics.............................................................................2-3

Remote Diagnostics ..............................................................................2-4

Indicators................................................................................................2-7

Printer Configuration...........................................................................2-9

Configuring the Printer................................................................2-11

Communication Interface............................................................2-14

RS-232C Serial Interface Settings................................................2-14

Printer Emulations........................................................................2-16

Printer Settings and Functions....................................................2-16

Enable or Disable Data Scope Mode..........................................2-19

Printhead Resistance....................................................................2-21

Chapter 3:

Troubleshooting

Service Level Troubleshooting............................................................3-1

Printer Tone and Green LED ........................................................3-1

iv Service Guide

Printing Problems...........................................................................3-2

Printer Does Not Function ............................................................3-5

Chapter 4:

Servicing the Printer

Tools Required.......................................................................................4-1

Service Procedure Map.........................................................................4-2

1, 2: Removing or Accessing the PC Control Board.........................4-3

Procedure.........................................................................................4-4

Re-installing the Control PC Board..............................................4-7

3, 4: Removing the Options PC Board................................................4-9

Procedure.........................................................................................4-9

Re-installing the Options PC Board...........................................4-10

5, 6: Removing the Rear Cover and Platen......................................4-11

Procedure.......................................................................................4-11

Re-installing the Rear Cover and Platen ...................................4-12

7: Removing the Platen/Fixed Knife Carrier Assembly................4-13

Procedure.......................................................................................4-14

Fixed Knife Blade/Platen-Carrier Assembly Removal.......4-15

Re-installing the Knife .................................................................4-15

8, 9, 10, 11: Removing the Top Cover Assembly, Paper Feed

Rod/Light Pipe, Reset Rod, and Paper Feed Button.....................4-16

Procedure (See illustration next page.)......................................4-16

R ......................................................................................................4-18

12: Removing the Paper Low Sensor/Mount.................................4-19

Procedure (See illustration next page.)......................................4-19

Re-installing the Paper Low Sensor/Mount.............................4-21

13: Removing the Thermal Mechanism...........................................4-22

Procedure.......................................................................................4-22

Re-installing the Thermal Mechanism.......................................4-25

14, 15, 16: Removing the Paper Out Switch, Knife Home

Switch, and Cover Open Switch.......................................................4-26

Procedure.......................................................................................4-26

Service Guide v

Re-installing the Paper Out Switch, Knife Home Switch,

and Cover Open Switch...............................................................4-27

17: Removing the Rotating Knife Blade...........................................4-28

Procedure.......................................................................................4-28

Re-installing the Rotating Knife Blade ......................................4-29

Cleaning the Printer............................................................................4-30

Cleaning the Printhead................................................................4-30

Revision Record

Issue Date Remarks

A Nov 98 First issue
B Mar 99 Updated
C June 99 Minor updates

D June 00 Updates

vi Service Guide

Radio Frequency Interference Statements

Federal Communications Commission (FCC)

Information to User

This equipment has been tested and found to comply with the limits for a Clas s A
digital device, pursuant to Part 15 of FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in
a commercial environment. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the instruction
manual, may cause harmful interference to radio communications. Operation of this
equipment in a residential area is likely to cause interference in which case the user
will be required to correct the interference at his own expense.

NCR is not responsible for any radio or television interference caused by unauthorized
modification of this equipment or the substitution or attachment of conn ecting cables
and equipment other than those specified by NCR. The correction of interference
caused by such unauthorized modification, substitution or attachment will be the
responsibility of the user. The user is cautioned that changes or modifications not
expressly approved by NCR may void the user’s authority to operate the equipment.

Canadian Department of Communications

This digital apparatus does not exceed the Class A limits for radio noise emissions
from digital apparatus set out in the Radio Interference Regulations of the Canadian
Department of Communications.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les
limites applicables aux appareils numériques de la classe A prescrites dans le
Règlement sur le brouillage radioélectriques édicté par le ministrère des
Communications du Canada.

Voluntary Control Council For Interference (VCCI)

Chapter 1:

Technical Specifications

Reliability

Thermal mechanism

45 Million Lin e s

Knife

1.5 Million Cuts

1-2 Chapter 1: Technical Specifications

Power Requirements

The printer receives power either from the host system (integrated) or
from a sepa rate in -lin e power su pp ly (remote) which ca n be purch as ed
separately

Power from Host (Integrated )

Voltage 24 Vdc ± 10%

+5 Volts for Logic Circuits

Amps 2 Amps Maximum Current Draw

Power from Power Supply (Remote) 55 Watts

Voltage 24 Vdc ± 10%

+5 Volt Supply for the Logic Circuits

Amps

Short Term (under 1ms)
25% Dot Coverage

9.0A Peak

2.3A Average

Power from Power Supply (Remote) 75 Watts

Voltage 24 Vdc ± 10%

+5 Volt Supply for the Logic Circuits

Amps

Short Term (under 1ms)
50% Dot Coverage

12.0A Pe ak

3.1A Average

Chapter 1: Technical Specific ations 1-3

Environmental Conditions

Without Knife
Operating Temperature
Operating Humidity

5°C to 35°C (41°F to 95°F)
5% to 90%

35°C to 50°C (95°F to
122°F)
5% to 40%

With Knife
Operating Temperature
Operating Humidity

5°C to 28°C (41°F to 82°F)
10% to 90%

28°C to 45°C (82°F to
113°F)
10% to 35%

Storage Temperature
Storage Humidity

-10°C to 50°C (14°F to 122°F)
5% to 90%

Transit Temperature
Transit Humi dity

-40°C to 60°C (-40°F to 140°F)
5% to 95%

Condensation

Condensation may occur when the printer is moved
from cold to warm areas after shipment. The printer's
design permits operation after drying out and
stabilizing at room temperature.

1-4 Chapter 1: Technical Specifications

Dimensions and Weight

Height

135 mm (5.34 inches)

Height with cover open

216 mm (8.53 inches)

Width

144 mm (5.66 inches)

Depth

184 mm (7.24 inches)

Weight

1.3 kg (2.9 pounds)

Chapter 1: Technical Specific ations 1-5

Printing Specifications

Speed

38.4 Lines per S eco nd ( Sta nd ar d Spac ing)

Printhead

Direct Thermal, Fixed Head, 640 Dots
(576 Addressable – 80.0 mm) (640 Addressable –

82.5 mm)

Paper Feed

130 mm per Second (Maximum)

1-6 Chapter 1: Technical Specifications

Density of Receipt Print Lines

This fun ct ion m ak es it possible to adjust the energy level of the
printh e a d t o darke n the printou t. An adjustment sh ould o n ly be ma de
when necessary. The factory setting is 100%.

Caution:

Choose an energy level no higher than necessary to achieve
a dark prin to ut. Failure to observe this ru le may result in a printer
service call or v oid in g o f the prin t e r warran ty. Consult your NCR
technica l s upport spe cia lis t if yo u ha v e any qu es ti on s.

When the prin t er prints high dens it y p r in t line s (t ext or graphics ), it
automatically slows down.

To change the Print Density:

1. Enter the Configuration Menu.

2. Select “Set Hardware Options” from Main Menu.

“Hardware Options Menu” is printed on the receipt and the
question “Set Print Density?” asked.

3. Answe r YE S (L ong click ) .

A warning is p rinted, followed by:
Print D ens ity

100% 1 Click
110% (+) 2 Clicks
120% (++) 3 Clicks

4. Enter code, then hold Button DOWN at least 1 second to validate.

Chapter 1: Technical Specific ations 1-7

Duty Cycle Restrictions (Printing Solid Blocks)

There are restrictions on the duty cycle because of the heat generated
by the the rmal printhead wh en prin ting solid blocks (regardless of the
length of the block in rela t ion
to the print line). The restrictions are ambient temperature, the
percentage of time (measured against one minute) of continuous solid
printing, and the amount of coverage.

Caution:

When the duty cycle approaches the limits shown in the
table, th e receipt printhead will h e at up and sh u t down. Th is may
damage the printhead.

To avoid th is p r oble m, do one or a combinatio n of the followin g :

1. Reduce the amount of coverage.

2. Reduce t he time of continuou s so lid printing.

3. Reduce the ambient temperature.

1-8 Chapter 1: Technical Specifications

Allow able Duty Cycle (measured over one minute of
conti nuo us pr int in g)

Amount of Solid Coverage Ambient Temperature

25°C35° C50° C
20% 100% 50% 20%
40% 50% 25% 10%
100% 20% 10% 4%

For reference:

•

A typical receipt with text (contains some blank spaces) is
approximately 12% dot coverage.

•

A full line of tex t chara cte rs (e v ery ce ll o n th e line h as a char act er in
it) is approximately 25% dot coverage.

•

Graphics are approximately 40% dot coverage.

•

Barcodes are approximately 50% dot coverage.

•

A solid black line is 100% dot coverage.

Chapter 2:

Diagnostics and Configuration

The following d ia g nostic tests are a va ila ble . S e e the sectio n s that follow
for more information.

• Startup Diagnostics

Performed during the startup cycle.

• Runtime Diagnostics

Performed during normal printer operation.

• Remote Diagnostics

Mainta in e d durin g n orma l o p e ra t ion an d pr in t ed in the prin t tes t.

The printer can be configured with the following settings and functions
throug h th e Config u ra t ion M enu th a t is prin t ed on the rece ip t. Se e
“Printer C onfig uration” in this do cume n t for more info rm a tio n.

• Communication Interfaces

• RS-232C Settings

• Printer Emula tio n s

• Printhe a d Re sistan c e

• Datasco pe Mode

2-2 Chapter 2: Diagnostics and Configuration

Startup Diagnostics

When the printer receives power or performs a hardware reset, it
autom at ica lly performs the Sta rt up Diagnostics (a ls o kno wn as Lev el 0
Diagnostics) during the startup cycle. The following diagnostics are
performed:

• Turn off motors

• Perform boot CRC check of the firmware ROM, test external

SRAM, test EEPROM, and test main program CRC
Failure causes Startup Diagnostics to stop; the printer beeps and

the LED flashes a set number of times, indicating the nature of the
failure. See the table in the “Indicators” section later in th is
document for the tone and LED sequences.

• Check if paper is present

• Return the knife to the home position

Failure ca u ses a fault condition. See the t a ble in th e “Indicators”
section lat e r in th is d ocument for the tone and L ED sequ e n ces.

• Check if receipt cover is clos ed

Failure does not interrupt the startup cycle.

When the Startup Diagnostics are complete, a two-tone beep (low then
high frequency) is heard, the Paper Feed Button is enabled and the
printer is ready for normal operation.

If the printer has not been turned on before, or a new EEPROM has
been ins t a lled , th e defa u lt valu es fo r the printer functions will be
loaded into the EEPROM during Startup Diagnostics.

Chapter 2: Diagnostic s and Conf i guration 2-3

Runtime Diagnostics

Runtime Diagnostics (s ome t im es calle d Le ve l 2 Diag n ost ics ) run
during normal printer operation. When the following conditions occur,
the printer automatically turns off the appropriate motors and disables
printing to prevent damage:

• Paper out

• Cover open

• Knife una ble to hom e

• Printhead too hot

• Voltages out of range

The LED on the ope ra t or pane l will signal when thes e co n dit io n s occu r
as well as in dica t e wh a t stat e or mo de th e pr in t e r is in.

For more information about See this section

Operator panel LED

NCR 7194 Troubleshooting

2-4 Chapter 2: Diagnostics and Configuration

Remote Diagnostics

Remot e diag nostics (som e times called Level 3 Dia g nostics) keeps t ra ck
of the followin g t a llies and prints them on the re ceipt during the print
test. Se e the sample test print o u t on th e next page. These tallies can be
used to determine the printer’s state of health.

• Model number

• Serial number

• CRC number

• Number of lin es prin t e d

• Number of knife cuts

• Number of hours the printer has been on

• Number of Flash cycles

• Number of cutter jams

• Number of times the cover is open

• Max imum tempe r ature re a ched

(See tallies note on the following page.)

Chapter 2: Diagnostic s and Conf i guration 2-5

2-6 Chapter 2: Diagnostics and Configuration

For more information about See this section

Accessing the remote
diagnostic tallies

“7194 Programming Information”
(Transmit Printer ID, Remote
Diagnostics Extension,
Hexadecimal 1D 49 40 n) in the
NCR

7194 Owner’s Guide

Chapter 2: Diagnostic s and Conf i guration 2-7

Indicators

The prin te r can comm un icat e some conditions v isu ally with the Green
LED or audibly with a series of tones or beeps. The following table lists
these indicators.

Indicator Sequence Condition

LED Continuous, flashing

quickly

Paper out
Cover off
Knife unable to home

LED Continuous, flashing slowly Paper is low

(if Paper Low Sensor is installed)
Printhead too hot
Voltages out of range

Tone Two-tone Beep

(low fre quenc y, high
frequency)

Startup Diagnostics completed
successfully

LED
and Tone

Single Beep
Single LED Flash

Boot CRC Test Failure

LED
and Tone

Double Beep
Double LED Flash

SRAM Test Failure

LED
and Tone

Triple Beep
Triple LED Flash

EEPROM Test Failure

LED
and Tone

Two-Tone Beep
(high frequency, low
frequency)

Continuous flashing of LED

Main Program CRC Test Failure
Or

DIP Switch is in On Pos it ion
indicating Flash Download Mode

2-8 Chapter 2: Diagnostics and Configuration

For more information about See this section

Error co n di t ions and correcting them “7194 Troubleshooting”

The prin t er is also able to communicate its stat us to t he h os t
applicat ion if t h e app licat io n h a s be en pro g ram m e d to rece iv e this
information.

For more information about See this section

Communication of printer status to
host application

“7194 Programming Information”
(“Printer Status ” commands) in
the NCR 7194 Owner’s Guide

Chapter 2: Diagnostic s and Conf i guration 2-9

Printer Configuration

Printers are shipped with all the functions and parameters pre-set at
the factory. Settings for various printer parameters can be changed.
This menu is printed on the receipt and scrolls through instru ctio ns for
selecting and changing any of the functions or parameters.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

The following functions and parameters can be changed with the
scrolling Configurat ion Me nu:

• Communication Interface

• RS-232C Interface

• IEEE 1284 Interface

• RS-232C Serial Interface Settings

• Baud Rate

• Data Bits

• Stop Bits

• Parity

• Hardware (DTR/DSR) or Software (X ON/ X OFF ) Flow Control

• Data Reception Errors

• Printer Emula tio n s

• 7194 Native Mode

• Epson TM-T88

• Printer Settings and Functions

• Defaul t Lin es per Inch

• Carriage Return Usage

• Data Scope Mode

2-10 Chapter 2: Diagnostic s and Conf i guration

• Power Supply Wattage

• Knife Optio n s

• Paper Low Sensor

• Printhead Resistance Setting

For more information about See this section

Using t h e con figuration m enu to
configu re t h e pr in t er

“Config u ring the
Printer”

Chapter 2: Diagnostic s and Conf i guration 2-11

Configuring the Printer

The Config u ra t ion M enu allows you to select functio n s o r ch a ng e
various settings for the printer. Instructions printed on the receipt
guide you through the processes.

Caution:

Be extremely careful changing any of the printer settings to
avoid changing other settings that might affect the performance of the
printer.

Off

Switch 1 is shown
in the ON position

On

DIP Switches

12

Back of Printer

1. Set DIP Switch 1 to ON position (down). DIP Switch 2 must always

be set to ON position (down).

2-12 Chapter 2: Diagnostic s and Conf i guration

Paper Feed

Button

Reset

Button

Rear
Cover

2. Open the Rear Cover. Insert paper roll as described in the

Owner’s

Manual

.

3. Press the Reset Button. Close the cover while holding the Paper

Feed Button.
The print e r beeps, prints the curren t configuration , then prin ts the

first question.

Chapter 2: Diagnostic s and Conf i guration 2-13

4. Follow all th e ins t ru ct ion s o n th e scrollin g menu.

5. Press the Paper Feed Button to make the selections.

The inst ruct ion s in d ica t e wh e t h e r to sele ct something with a sh o rt
click, a long click, or a series of short clicks . In d icat e Y es wit h a long
click, No with a short click.

Press and hold the Paper Feed Button for at least one second for a
long click. Press the Pape r Fee d But t on quickly for a short click.

6. When you have finished, set DIP Switch 1 to Off.

7. Press the Reset button.

The printer resets with the new selections.

2-14 Chapter 2: Diagnostic s and Conf i guration

Communicati on Interfac e

To change the Communication Interface settings, enter the
Config u r at io n M enu, sele ct “Set Communicati on Interface” from the
Main Menu and answer Yes to “SET INTERFACE TYPE?” printed on
the receipt.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed to select the communication
interface you want.

• Communication Interface

• RS-232C Interface:1 click

• IEEE1284 Interface: 2 clicks

RS-23 2C Serial Interface Setti ngs

To change the RS-232C Serial Interface settings, enter the Configuration
Menu, se l e ct “Set Communication Interface” from the Main Menu and
answer No to “SET INTERFA CE TYPE ?” printed on the receipt. Th is
will take you to the instructions for selecting the RS-232C settings.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed on the configuration menu to
select the RS-232C settings you want to change.

• Baud Rate

• 115200 baud: 1 click

• 57600 baud: 2 clicks

• 38400 baud: 3 clicks

• 19200 baud: 4 clicks

• 9600 baud:5 clicks

Chapter 2: Diagnostic s and Conf i guration 2-15

• 4800 baud:6 clicks

• 2400 baud:7 clicks

• 1200 baud:8 clicks

• Number of Data Bits

• 8 Data Bits: Long click

• 7 Data Bits: Short click

• Stop Bits

• 1 Stop Bit: Long click

• 2 Stop Bits:Short click

• Parity

• Enabled: Long click

• Disabled : Sho rt click

• No/Even/Odd Parity

• No Parity: 1 click

• Even Pa rity: 2 clicks

• Odd Parity: 3 clicks

• Hardware Flow Control

• Software (XON/XOFF ): Long click

• Hardware (DTR/DSR): Short click

• Data Reception Errors

• Ignore Errors: Long click

• Print “?”: Short click

Note:

Press the Paper Feed Button for at least one second to validate

the selection.

For more information about See this section

2-16 Chapter 2: Diagnostic s and Conf i guration

Setting the RS-232C Serial interfa c e settings “Configuring the Printer”

Printer Emulations

To change the Printer Emulations settings, enter the Configuration
Menu, se l e ct “Emulation/Software Options” from the Main Menu and
answer Yes to “SET THE PRINTER EMULATIONS?” printed on the
receipt. This will take you to the inst ru ct ions for se tt ing the prin te r
emulation.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed to select the printer
emulation you want.

•

7194 Native Mode: 1 click

•

Epson TM-T8 8: 3 clicks

Note:

Press the Paper Feed Button for at least one second to validate

the selection.

For more information about See this section

Setting the printer emulation “Configuring the Printer”

Printer Settings and Functions

To change the printer settings and functions, enter the Configuration
Menu, select the sub-menu from the Main Menu and answer the
quest ions prin t e d on the re ce ip t un t il you com e to t he inst ru ct ions for
selecting the printer settings.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed to select the printer settings
you want.

Chapter 2: Diagnostic s and Conf i guration 2-17

Select the Emulation/ So f twar e Options sub-m enu to set:

• Defaul t Lin es per Inch

This function allows you to set the default for Lines Per Inch to
either

8.13, 7.52, or 6.00.

• 8.13 Lines per Inch: 1 click

• 7.52 Lines per Inch: 2 clicks

• 6 Lines p e r Inch : 3 clicks

• Carriage Return Usage

This function allows the printer to ignore or use the Carriage
Return (hexadecimal 0D) command depending on the application.
Some app licat io n s expect the comm and t o be ig n o red while ot h e rs
us e the comm and as a pri nt com man d.

• Ignore Carriage Return: Long click

• Use Carriage Return as print command: Short click

Select the Diagno stic Modes sub-menu to set:

• Data Scope Mode

See “Enable or Di sa ble Dat a Scope Mo d e” later in this docum ent
for more information.

Select the Hardware Optio ns sub-m enu to set:

• Print D ens ity

• 100% 1 click

• 110% 2 clicks

• 120% 3 clicks

Warning:

Choose a print density setting no higher than nece ssar y to
achieve acceptable pr int density. Failure to observe this rule may
result in a printer se rvice ca ll. Failure to observe this r ule may vo id
the printer warranty. Consult your NCR technical support specialist
if you have questions.

2-18 Chapter 2: Diagnostic s and Conf i guration

• Power Supply Wattage

You can choose between a 48 Watt, 55 Watt or 75 Watt power
supply.

• 48 Watt Power Supply: 1 click

• 55 Watt Power Supply: 2 clicks

• 75 Watt Power Supply: 3 clicks

• Knife Optio n

• Knife Enable d:Long click

• Knife Dis able d: S h ort click

• Paper Low Sensor

• Paper Low Sensor Enabled: Long click

• Paper Low Sensor Disabled: Short click

• Printhead Resistance Setting

• See “Printhead Resistance” later in this document for more

information.

Note:

Press the Paper Feed Button for at least one second to validate

the selection.

For more information about See this section

Setting the printer functions and settings “Configur ing t he Printer”

Enabl e or Disable Data Scope Mode

The Data Scope Mode test prints a hexadecimal dump of all data sent
to the printer: “1” prints as hexadecimal 31, “A” as hexadecimal 41 and
so on. This h elps troublesh oo t communication p r oble m s a n d runs
during a no rmal application (afte r be in g e n a bled t h roug h p rin t e r
configuration).

Chapter 2: Diagnostic s and Conf i guration 2-19

Note:

Data Sco pe Mode is usually considered a Lev e l 1 diagn o stic

test.

Data Scope Mode is enabled and disabled by selecting the “Diagnostic
Modes” sub-menu of the Con figuration Men u.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed on the “Diagnostic Modes
Menu” to enable or disable the Data Scope Mode test.

• Off, Normal Mode (Data Scope Mode disabled): 1 click

• Data Scope Mode (en able d): 2 click s

• Receipt Te st Mode: 3 clicks

Note:

Press the Paper Feed Button for at least one second to validate

the selection.

To run the Data Scope Mode:

1. After you have enabled the Data Scope, exit the Configuration

Menu.

2. Run a tran sact i on from the h o st computer.
All comm ands and data sent from the hos t comp uter will be printed as

hexade cim a l ch a ra ct ers as sh own in the illu stration.

To exit the Data Scope Mode:

1. Enter the Configuration Menu again.

See “Configuring the Prin t er.”

2. Disable the Data Scope Mode.

2-20 Chapter 2: Diagnostic s and Conf i guration

3. Exit th e Co n figu r a t ion Me nu .
The prin te r is on-line and can commun ica te n o rma lly wit h the host

computer.

For more information about See this section

Enabling t he Da ta Sco pe Mo de “Config u r ing the P r in t e r”

Chapter 2: Diagnostic s and Conf i guration 2-21

Printhead R esistance

The printhead resistance settings are set by entering the Configuration
Menu, selecting “Set Hardware Options” and answerin g N o to the
quest io ns prin te d on the rece ip t until you come to “SET PRINTHEAD
SETTING?”.

The printhead resistance setting must match the character (A or B)
stamped on the heatsink on the back of the printhead. This is visible by
removing the top cover of the printer, which can only be removed by a
trained service representative.

Caution:

Be extremely careful changing any of the printer settings to
avoid inadvertently changing other settings that might affect the
performance of the printer.

Press the Paper Feed Button as instructed on the Configuration Menu
to select the printhead resistance setting:

• A Setting: Long click

• B Setting: Short click

Note:

Press the Paper Feed Button for at least one second to validate

the selection.

For more information about See this section

Setting the printhead resistance “Configur ing th e P r in t e r”

2-22 Chapter 2: Diagnostic s and Conf i guration

Chapter 3:

Troubleshooting

Service Level Troubleshooting

The printer is simple and generally trouble-free, but from time to time
minor problems may occur. Follow these procedures to determine the
cause and resolution of any problems the printer may be having.

Printer Tone and Green LED

Problem Possible Causes What to Do Where to Go

Green LED, quick
continuous flashing.

Paper out.
Cover off.
Knife unable to home.

Put in a new paper roll.
Put the cover on.
Check the knife. It may
need to be replaced.

7194 Owner’s Guide

7194 Service Guide

Green LED, slow
continuous flashing.

Paper is low (if Paper Low
Sensor is installed).

Continuous printing of
graphics (regardles s of
room temperature),
causing the printhead to
overheat.

Power supply voltage is
out of rang e .

Put in a new paper roll.

Reduce the demand on
the printer.

Measure the voltage with
an AC voltmeter and
check it against the power
supply label. The v o ltag e
range should be 24V ±
10%.

7194 Owner’s Guide

Double Beep.
Double LED Flash.

SRAM Test Failure. Run Startup Diagnostics

again. If this does not
wo rk, replace the Cont rol
PC Board.

7194 Service Guide

Triple Beep
Triple LED Flash.

EEPROM Test Failure. Run Startup Diagnosti cs

again. If this does not
wo rk, replace the Cont rol

7194 Service Guide

3-2 Chapter 3: Troubleshooti ng

PC Board.

Two-Tone Beep
(high frequency, low
frequency)

Continuous flashing
of LED.

Main Program CRC Test
Failure.

DIP Switch is in On
Position indicating Flash
Download Mode.

Run Startup Diagnostics
again. If this does not
wo rk, replace the Cont rol
PC Board.

Put DIP Switch in Off
position fo r n ormal
operation.

7194 Service Guide

7194 Service Guide

Printing Problems

Problem Possible Causes What to Do Where to Go

Colored stripe on
the receipt.

Paper is low. Change the paper. 7194 Owner’s Guide

Receipt does not
come out all the
way.

Paper is jammed. Open the receipt cover,

inspect the knife, and clear
any jammed paper.

Printer starts to
print, but stops
while the receipt is
being printed.

Paper is jammed. Open the receipt cover,

inspect the knife, and clear
any jammed paper.

Receipt is not cut. Paper is jammed.

The printer is not
co nfig ured f or a kn ife.

The Knife Home Sensor
may be defective.

Knife Home Sensor not
plugged in.

Open the receipt cover,
inspect the knife, and clear
any jammed paper.

Enable the knife option by
reconfiguring the printer.

Check Knife Home Sen sor
with an ohmmeter at its
harness and test point, and
replace it if defective.

Check connections to the
PC Board.

7194 Service Guide

7194 Service Guide

7194 Service Guide

7194 Service Guide

Chapter 3: Troubleshoot i ng 3-3

Problem Possible Causes What to Do Where to Go

Failure of the Knife Motor
or Knife Home S e nsor.

Replace the Knife Hom e
Sensor first, then the Knife
Motor if problem still exists.

Print is light or
spotty.

Printhead resistance not
properly set.

Paper roll loaded
incorrectly.

Thermal printhead is dirty.

Improper cable
connections.

Variations in paper.

Printhead is defective.

Adjust the printhead
resistance.

Check that the paper is
loaded properly.

Use recommended thermal
receipt paper.

Clean thermal printhead
with rubbing alcohol and
co t ton sw abs.

Check thermal printhead
cable connections.

Increase print density in
“Set Hardware Options” of
printer Configuration Menu
to 110% or 120% as needed.

Replace Thermal
Mechanism.

7194 Service Guide

7194 Owner’s Guide

7194 Owner’s Guide

7194 Service Guide

7194 Service Guide

7194 Service Guide

Warning: See the
section “Printer
Settings and
Functions”.

Vertical column of
print is missing.

Printhead is defective. Replace Thermal

Mechanism.

7194 Service Guide

One side of receipt
is missing.

Printhead is defective. Replace Thermal

Mechanism.
If this does not help, replace

the printhead.

7194 Service Guide

3-4 Chapter 3: Troubleshooti ng

Problem Possible Causes What to Do Where to Go

*

Do not spray the thermal printhead with household cleaner as this may damage it and the electronics. The
thermal printhead does not normally require cleaning if the recommended paper grades are used. If non­recommended paper has been used for an extended period of time, cleaning the printhead with rubbing
alcohol and cotton swabs will not be of much benefit.

Chapter 3: Troubleshoot i ng 3-5

Printer Does Not Function

Problem Possible Causes Wh at to Do Where to Go

Printer Does N ot
Function.

Printer not plugged in. Check that printer cables

ar e properly co nnected
on both ends. Make sure
the ground wire is
properly connected.

Check that the host or
power supply is getting
power.

7194 Service Guide

7194 Service Guide

Receipt cover not fully
closed.

Close and latch the
receipt cover.

Cables wi thin the
printer are improperly
connected to the PC
board.

Make sure the cables in
the printer are properly
connected to the PC
board.

7194 Service Guide

Printer is not correctly
configured.

Check the printer’s
configuration and
reconfigur e if necessary.

7194 Service Guide

Power Voltage too
Low/High.

Check that all cable
connections are correct
and that the power
supply (if present) is
plugged in and the
printer is on-line.

7194 Service Guide

Power supply voltage
is out of range.

Measure the voltage with
an AC voltmeter and
check it against the
power supply label. The
vo ltage ra nge sh ould be
24V ± 10%.

3-6 Chapter 3: Troubleshooti ng

Operating printer in a
room where
temperature is above
recommended
temperature, causing
the printhead to
overheat.

Adjust the room
temperature.

Move the printer to a
cooler location.

Continuous print ing o f
graphics (r egardless of
room temperature),
causing the printhead
to overheat.

Reduce the demand on
the printer.

Operating printer in a
room where
temperature is below
recommended
temperature, causing
the printhead to not
function properly.

Adjust the room
temperature.

Move the printer to a
warmer location.

Note: The printer will shut off when it is over or
under temperature. See the reference for the
recommended temperature range.

7194 Service Guide

Failed PC Board. Replace the PC

Board.

7194 Service Guide

Printer Cyc l es But
Doe s Not Print.

Cable con necting th e
printhead to the PC board is
not prope rly connecte d.

Check the cable
connection to the
printhead and to the
PC board.

7194 Service Guide

Chapter 4:

Servicing the Printer

Tools Required

• #1 Pozidriv screw driver

• #2 Pozidriv screwdriver

• Equivalent Phillips Screwdrivers

• Flat-blade screwdriver

4-2 Chapter 4: Servicing t he Printer

Service Procedure Map

2

.

Removeo

r

Acce ss

theContro

l

Board

4

.

RemovetheOptions

B

oard

6

.Remove

the

Plate

n

3.

R

emoveth

eRearDoor

5.

R

emoveth

e

R

earCove

r

7

.

RemovethePlaten/Fixed

Knife

CarrierAsse

mbly

13.

Rem

oveth

e

Ther

malMechanis

m

1

0.

Reset Rod

9.

Paper Feed Rod/
Light P ipe

11.

PaperFeedButton

12.

Paper

Low

Senso

r

/Mount

1.

R

emoveth

eBasePlat

e

7

11

94 Printer S

erviceProcedureMa

p

14.

Paper O ut Switch

15.

K

nife HomeSwitch

16.

CoverOpenSwitch17.RotatingK

nife Blade

8.

Rem

ovetheTop

Cov

erAssembl

y

Chapter 4: Servicing the Printer 4-3

1, 2: Removing or Accessing the PC Control Board

The Control PC Board is accessed by removing the Base Plate of the
printer. You will need to access th e Cont rol PC Bo a rd to disconnect
wires connected to items you are removing, or to replace the Board
because it ma y h a ve beco m e defe ct iv e or you are upgrading the
memory.

Note:

The entire Control PC Board must be replaced to upgrade the

memory.

Tools: Pozidriv #1 (required only if removing Control PC Board) and
#2 screwdrivers.

4-4 Chapter 4: Servicing t he Printer

Procedure

To Access the Co n tr ol PC Board:

Screw

Base Plate

1. Open the Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or Options
PC boards. Wear a grounded wrist strap and use a static mat or other
ESD protected work surface when handling electronic components.

3. Close the Cover and place the printer on its front with the bottom

facing yo u (as sh own above.)

4. Remove the screw holding the Base Plate to the cabinet. Place to the

side for reuse.

Chapter 4: Servicing the Printer 4-5

5. From the right side, carefully swing the base plate out and towards

the right to unhinge the left side of the plate from the tabs in the
cabinet. (See page 7.) Lower the base plate away from the printer
cabinet and lay it on a flat work surface.

6. Disconnect the appropriate wires from the Control PC Board.

Note:

If accessing the Control PC Board to disconnect wires only, you

do not need to continue.

J11 Control PC
Board Connector

J6 Cover Open
Switch Conn ector

J5 Paper Feed
Motor Connect or

J15 Knif e Hom e
Switch Connector

J7 Paper Out
Switch Connector

J8 Pa per Low
Switch Connector

J17 Knife Motor
Connector

J10 P r int Head
Connector

Connector Location and Designations

4-6 Chapter 4: Servicing t he Printer

To remove the Control PC Board:

Screws

Lock

Washers

Options
PC Board

Control
PC Board

Base
Plate

Shield

Screw

Lock
Washer

Chapter 4: Servicing the Printer 4-7

After accessing the Control PC Board and disconnecting all the wires:

1. Remove the two screws holding the Options PC Board to the Base

Plate.

2. Unplug the Options PC Board from the Control PC Board and

remove.

3. Lift the Control PC Board up and out of the Base Plate. The Shield

remains in the Bas e Plat e .

Re-installing the Control PC Board

Reverse the previous procedures to re-install the Control PC Board into
the Base Plate.

Caution:

When replacing the Options PC Board, ensure proper
alignment of the connector on the Options PC Board with the
connector on the Control PC Board. Guides on the Base Plate are
provided t o help with this alignm e n t.

Re-inst a ll th e Base Plate (with the Control PC B oa rd ) by:

1. Aligning the tabs inside the left side of the Cabinet with the slots in

the Base Plate.

2. Place the slots over the tabs and swing the other side of the Base

Plate into place.

Note:

Note: Carefu lly position the Control PC Board wire harnesses

into the cavity to prevent them from being pinched or damaged.

3. Re-install the screw into the right side of the Base Plate.

4-8 Chapter 4: Servicing t he Printer

Tabs in
Cabinet

Options PC

Board

Option s PC Bo ar d
Connector

Contro l PC
Board Conn ect or

Opti o ns PC

Board Guides

Base
Plate

Slots in

Base Plate

Control
PC Board

Chapter 4: Servicing the Printer 4-9

3, 4: Removing the Options PC Board

The Options PC Board can be replaced if it becomes defective, or
should there be a need to change the communication interface. The
Options Board can be accessed from the back of the printer by
removing the Connector Cover.

Tools: Pozidriv #1 screwdrivers

Procedure

1. Open Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

3. Clo se the Rear Cover and turn printer with bac k fac i ng you.

4. Remove the Connector Cover by unsnapping the hinges on each

side.

5. Unscrew the two screws holding the Options PC Board Mounting

Plate to the printer cabinet.

6. Pull the Opt ions PC Boar d o u t toward you (th is will disconnect t h e

Options PC Board from the Control PC Board).

4-10 Chapter 4: Servicing the Printer

Back of

Printer

Options PC Board

Mounting Plate

Base
Plate

Connector Cover

Screws

Re-installing the Options PC Board

Reverse the proced ures abo ve to re-install t he Op tions PC Board.

Caution:

When replacing the Options PC Board, ensure proper
alignment of the Options PC Board connector with the connector on
the Control PC Board. Guides on the Base Plate are provided to help
with this alignment.

Chapter 4: Servicing the Printer 4-11

5, 6: Removing the Rear Cover and Platen

The Rear Cove r will need t o be removed to repla ce the plat en o r to
access the Fixed Knife Carrier Assembly.

The Platen will n ee d t o be remove d if it is worn or contaminated, or if a
gear or th e Pa per guide becom es br oken.

Tools: No tools are required.

Procedure

1. Open the Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

3. Remov e th e Re a r Co ve r by pushing out slight ly o n eit h e r side o f

the Cover where it attaches to the Top Cover Assembly. Lift the
cover up and away

4. Set the Rear Cover on a flat surface and pull the gear end of the

Platen up and out of the Platen – Carrier Assembly, removing the
Paper Guide wit h it.

4-12 Chapter 4: Servicing the Printer

Paper
Guide

Bearing

Platen

Platen-Carrier
Assembly

Rear
Cover

Push out slightly
to remove cover

Gear

Re-installing the Rear Cover and Platen

Reverse the previous procedure to re-install the Platen.

1. Re-ins ta ll t h e Pla t e n by s nap ping it into place, rig ht-side bearing

first, into the Platen-Carrier Assembly with the gear to the left.

Note:

The Paper Guide should be flush against the Fixed Knife Blade,

if installe d. A slight gap on the righ t sid e is norm a l.

After installation, rotate the Platen to ensure it moves freely.

Chapter 4: Servicing the Printer 4-13

7: Removing the Platen/Fixed Knife Carrier
Assembly

The following information describes the procedure to service the
Platen/Fixed Knife Carrier Assembly.

The knife consists of two separate parts: the Fixed Knife Blade, within
the Platen Carrier Assembly on the Rear Cover, and the Rotating Knife
Blade located on the Thermal Mechanism.

Whenever any part of the knife is replaced, both the Fixed Knife Blade
(Platen Carrier) and Rotating Knife Blade must be replaced.

Example: If the Thermal Mechanism is replaced, the Fixed Knife Blade
(part of the Platen Carrier Assembly) must also be replaced (see page
27 for removing the Rotating Knife Blade.)

Tools: Pozidriv #1, #2

4-14 Chapter 4: Servicing the Printer

Fixed Knife Blade within
Platen Carrier Assembly

Rear
Cover

Rotating Knife Blade on
the Thermal Mechanism

Procedure

1. Open Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

To Remove the Fixed Knif e Blade (Platen Car r ie r Assem bly ):

1. Remov e th e Re a r Co ve r by pushing out slight ly o n eit h e r side o f

the Cover where it attaches to the Top Cover Assembly. Lift the
cover up and away. (See page 11.)

Chapter 4: Servicing the Printer 4-15

2. Set the Rear Cover on a flat surface and remove the three screws

and lock was h e rs h o lding the P la t en Carrie r As sembly to the Rea r
Cover. (See illu stration next page.)

Rear
Cover

Platen-Carrier
Assembly

Lock Washer
(3 Pls.)

Screw (3 Pls.)

Fixed Knife Blade/P l aten-Carrier Assembly Removal

To Remove the Rotating Knife Blad e:

See “Removing the Rotating Knife Blade” on page 27 of this document.

Re-installing the Knife

Reverse the previous procedure to re-install the Fixed Knife Carrier
Assembly. There is no adjustment necessary.

See page 28 for re-installing the Rota t ing Knife Bla de .

4-16 Chapter 4: Servicing the Printer

8, 9, 10, 11: Removing the Top Cover Assembly,
Paper Feed Rod/Light Pipe, Reset Rod, and Paper
Feed Button

To remove or replace the Paper Feed Rod/Light Pipe, Reset Rod, and
Paper Feed But to n, you will nee d to rem ov e the Top Cov e r Asse mbly.

Tools: Flat-blade screwdriver

Procedure (See illustration next page.)

1. Open Rear Cover and remove the paper from the printer. Leave the

cover op en.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

3. Remove the Top Cover Assembly by pushing the two tabs at the

bottom rear of the paper bucket towards the back with a flat-blade
screwdriver. Place the Top Cover Assembly on a flat surface

4. Remove the Paper Feed Rod/Light Pipe from the front right of the

Printer Ba se, by lifting it up and ou t of the slot . Not e it s position for
reinstallation.

5. Remov e the R ese t Rod on t he le ft sid e of the un it by lifting it up

and out of the slotted holder in the base. Note its position for
reinstallation.

6. Tip the Top Cover Assembly up to access the Paper Feed Button

from below. Remove the button by pinching in on the two outer
tabs until the button pops up. Continue to push on the center tab
until the button can be removed. Note the compression spring
around the center tab.

Chapter 4: Servicing the Printer 4-17

ear
over

Paper Feed
Button

Compression
Spring

Top Cover
Assembly

Paper Feed
Rod/Light
Pipe

Reset
Rod

Tabs

Hook

Hook

Printer
Base

Pinch Tabs

Tab locations in
Paper Bucket

4-18 Chapter 4: Servicing the Printer

Re-installing the Paper Feed Rod/Light Pipe, Reset Rod, and
Paper Fe ed Butt o n

To install the Paper Feed Butto n into the Top Cover Assemb ly :

1. Ensure Compression Spring is around the center tab of the button.

2. Guide th e butt on in t o the open ing in th e Top C ov er Ass em bly ,

ensuring the spring remains in place.

3. Push the button in until it snaps into place. Test the button to

ensure the spring operates properly.

To install the Reset Rod and Paper Feed Rod/Light Pipe:

1. Reverse the removal procedures for the Rods to install them.

Ensure that they seat properly in their positions. Once you have
reinstalled the Paper Feed Button and Rods, re-install the Top
Cover Assembly.

To install the Top Cover:

1. With the Rear Cover open, tilt the Top Cover Assembly towards

you and align the hooks on the front with the tabs in the base.

2. Lower the back o f Top C over As s embly and snap it into place.

3. Check the tabs at the rear of the bucket to ensure they have fully

engaged. Use a screwdriver if necessary to pry them until they snap
over the cover.

Chapter 4: Servicing the Printer 4-19

12: Removing the Paper Low Sensor/Mount

Assem bly / d is ass embly procedur e to serv ice t h e Pa per Lo w
Sensor/Mount.

Tools: Flat-blade screwdriver

Procedure (See illustration next page.)

1. Open the Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or Options
PC boards. Wear a grounded wrist strap and use a static mat or other
ESD protected work surface when handling electronic components.

3. Remove the Top Cover Assembly by pushing the two tabs at the

rear of the paper bucket towards the back with a flat-blade
screwdriver. Lift the cover off the Base.

4. Access the Control PC Board. (See page 3.)

a. Place the printer on its front with bottom facing you.
b. Remov e the s crew i n the B ase P late.
c. Swing the right side of the Base Plate towards you and to the

right to release it from the tabs in the cabinet. Lower the Base
Plate onto a flat surface.

5. Unplug the Paper Low Sensor wire from the Control PC Board

connector, J8 and feed the wire up through the opening in the Base.

6. Remove the Paper Low Sensor.

a. Pry off the two Push Clips that hold the Sensor to the Paper

Low Mount. Set the Sensor aside.
If necessary, remove the Paper Low Mount by removing the

screw holding it in place.

4-20 Chapter 4: Servicing the Printer

Rear
Cover

Top Cover
Assembly

Tabs

Hook

Hook

Printer
Base

crew

Lock
Washer

Push
Clips

Paper Low
Sensor

aper Low

ount

Chapter 4: Servicing the Printer 4-21

Re-installing the Paper Low Sensor/Mount

To install th e Paper L ow Sensor/ M oun t:

1. If the Top Cover Assembly and Prin te r Bas e a re st ill removed,

complete the installation by going to step b. If not, remove the Top
Cover Assem bly an d Prin te r Bas e.

2. Fasten the Pap er Low M ount (if rem ov ed ) with th e scre w.

3. Place the Paper Low Sensor onto the Paper Low Mount.

4-22 Chapter 4: Servicing the Printer

13: Removing the Thermal Mechanism

Assem bly /disassembly procedure to service t h e The rmal Mechanism.
You must replace the entire mechanism if any individual part is faulty.

The Platen-Carrier Assembly (part of the Top Cover Assembly and
containing the Fixed Knife Blade) must be replaced whenever the
Thermal Mech a n ism (containing the Rot a tin g Kn ife Bla de ) is re p la ced .
See “Removing the Platen/Fixed Knife Carrier Assembly” on page 13.

Tools: Pozidriv #1, #2

Procedure

1. Open the Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

3. Remove the Top Cover Assembly by pushing the two tabs at the

rear of the paper bucket towards the back with a flat-blade
screwdriver. (See page 16.)

4. Access the Control PC Board.

a. Place the printer on its front with the bottom facing you.
b. Remov e the s crew i n the B ase P late.
c. Swing the right side of the Base Plate towards you and to the

right to release it from the tabs in the cabinet. Lower Base Plate
onto a flat surface.

5. Disconnect all wires from the Control PC Board.

Note:

For ease of ins t alla t ion , it is qu ick e r t o d iscon n e ct a ll the wires,
even though not all wires need to be disconnected for Thermal
Mechanism replacement.

Chapter 4: Servicing the Printer 4-23

6. While sup p o rt ing the Ther m a l Mechanism with on e hand , remove

the screw holding it to the Base Plate . (See illu stration on next
page.) Lay the Printer Base flat on the surface.

7. Remove the Ground Wire from the Tear Bar.

8. Lift the Thermal Mechanism up and out of the Base.

9. Replace the Platen-Carrier Assembly on the Rear Cover. (See page

13.)

This assembly contains the Fixed Knife Blade that must be replaced
whenever the Thermal Mechanism is replaced.

4-24 Chapter 4: Servicing the Printer

Tabs

Rear
Cover

Top C over
Assembly

Hook

Hook

Thermal
Mechanism

Tear
Bar

Ground
Wire

Screw

Printer
Base

Platen Car rie r
Assembly

Re-installing the Thermal Mechanism

Reverse the procedures to re-install the Thermal Mechanism.

Chapter 4: Servicing the Printer 4-25

14, 15, 16: Removing the Paper Out Switch, Knife
Home Switch, and Cover Open Switch

Assem bly / disassembly proce dure to service the Paper Ou t Switch,
Knife Home S witch, and Cover Open Switch .

Tools: Pozidriv #1, #2

Procedure

1. Open the Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or
Options PC boards. Wear a grounded wrist strap and use a static mat
or other ESD protected work surface when handling electronic
components.

3. Remove the Top Cover Assembly by pushing the two tabs at the

rear of the paper bucket towards the back with a flat-blade
screwdriver. (See page 16.)

4. Access the Control PC Board.

a. Place printer on its front with the bottom facing you.
b. Remov e the s crew i n the B ase P late.
c. Swing the right side of the Base Plate towards you and to the

right to release it from the tabs in the Cabinet. Lower Base Plate
onto a flat surface.

5. Trace the wire(s) from the switch(es) to be removed to the

connector on the Control PC Board and disconnect. (J7 – Paper Out
Switch, J5 - Knife Home Switch, J6 – Cover Open Switch.)

6. While sup p o rt ing the Ther m a l Mechanism with on e hand , remove

the screw holding it to the Base Plate. (See previous page.) Lay the
Printer Base flat on the surface.

7. Remove the Ground Wire from the Tear Bar.

4-26 Chapter 4: Servicing the Printer

8. Lift the Thermal Mechanism up and out of the Base.

9. Remove the switch or switches.

a. Paper Out Switch: Turn the Mechanism over. Pry out the two

posts hold in g th e swit ch in place. Pull th e sw itch up and out
rotating it slig h t ly to allow t h e arm t o clear.

b. Knife Home S wit ch : R emo v e the scre w h old in g t h e s witch to

the right side. Note wire routing for future reference.

c. Cover Open Swit ch : Ca refully pry the switch o u t from th e righ t

side of the Mecha n ism. Note wire routing for rein st a llat ion .

Paper Out
Switch

Knife Home
Switch

Screw

Cover Open
Switch

Thermal
Mechanism

Re-installing the Paper Out Switch, Knife Home Switch, and
Cover Open Switch

Reverse the procedures to re-install the Paper Out Switch, Knife Home
Switch, and Cover Open Switch.

Note:

If wires were removed, ensure they are routed as before.

Chapter 4: Servicing the Printer 4-27

17: Removing the Rotating Knife Blade

Assem bly / d isassembly pro ced u r e to serv ice the Rotating Kn ife B la de.

Note:

Whenever any part of the knife is replaced, both the Fixed Knife

Blade (Platen Carrier) and Rotating Knife Blade must be replaced.

See “Removing the Platen/Fixed Knife Carrier Assembly” (page 13) for
information o n rem ov ing the fix ed Knife B lad e.

Tools: Pozidriv #1, #2

Procedure

1. Open Rear Cover and remove the paper from the printer.

2. Disconnect all the cables from the printer.

Caution:

Electrostatic Discharge could damage the Control or Options
PC boards. Wear a grounded wrist strap and use a static mat or other
ESD protected work surface when handling electronic components.

3. Remove the Top Cover Assembly by pushing the two tabs at the

rear of the paper bucket towards the back with a flat-blade
screwdriver.

4. Access the Control PC Board.

a. Place printer on its front with the bottom facing you.
b. Remov e the s crew i n the B ase P late.
c. Swing the right side of the Base Plate towards you and to the

right to release it from the tabs in the Cabinet. Lower the Base
Plate onto a flat surface.

5. Remove the Thermal Mechanism. (See page 22.)

a. Remove the screw holding the Actuating Arm to the Rotating

Knife Blade.

b. Remove the Actuating Arm.

4-28 Chapter 4: Servicing the Printer

c. Push the Rotating Knife Blade towards the back until the

Bearings sna p free from th e Thermal Mechanism. Lift the
Rotating Knife Blade up and out.

Thermal
Mechanism

Bearing

Rotating

Knife

Blade

Bearing

Screw

Actuating A rm

(with Slot)

Drive Gear

(with Drive Pin)

Re-installing the Rotating Knife Blade

Reverse the procedures to re-install the Rotating Knife Blade. There is
no adjustment necessary.

Note:

When repositioning the Actuating Arm, ensure the Drive Pin on

the Drive Ge a r is ins e rt ed in t o th e slo t in Actu a ting Arm.

Chapter 4: Servicing the Printer 4-29

Cleaning the Printer

Clean the outside cabinet as needed to remove dust and finger marks.
Use any household cleaner made for plastics. Test it first on a small
unseen area. Clean the receipt paper bucket with a clean, damp cloth.
The cabinet materials and finish are durable and resistant to the
following it e ms :

• Cleaning solutions

• Lubricants

• Fuels

• Cooking oils

• Ultraviole t lig h t

Cleaning the Printhead

Caution:

Do not try to clean the inside of the printer with any cleaner.
Do not try to clean t h e The rmal P r in the ad or allow spray to come in
contact with it. Damage to the internal electronics or Thermal
Printh e ad co u ld occur.

If the printhead appears dirty, wipe it with rubbing alcohol and cotton
swabs.

Do not use the alcohol to clean other parts of the printer. Damage will
occur.

Note:

The thermal p rinthead does not normally req u ire clean in g
when recommended paper grades are used. If non-recommended
paper is used over an extended period, attempting to clean the
printh ea d will h a ve litt le e ffe ct o n the prin t qua lit y .

If spott y or ligh t prin t in g p r oble ms persist afte r cle aning the therma l
printhead, the entire thermal mechanism may need to be replaced.

For more information about See this section

Removin g the therma l
mechanism

“13. Removing the Thermal Mechanism”

4-30 Chapter 4: Servicing the Printer

Index

—A—

Accessing

control board, 4-3

—B—

Beep.

See

tone

—C—

Carriage return usage, 2-17
Cleaning

printer, 4-29
printhead, 4-29

Colored stripe

indicating paper low, 3-2

Colum n of prin t

missing, 3-3
Communication interface, 2-14
Configuration, 2-9

carriage return usage, 2-17

communication interface, 2-14

configur in g the printer, 2-11

data scope mode, 2-18

default line s per inch, 2-17

knife option, 2-18

paper low sensor, 2-18

power supp ly wa t tag e , 2-1 8

printer emulations, 2-16

printer settings and functions, 2-16

printhead resistance, 2-21

RS-232C settings, 2-14

Conne ct or lo cat io n s

PC board, 4-5

Control board

removing, accessing, 4-3

Control PC board

connecto r lo ca t ions, 4-5
re-installin g, 4-7

Cover open switch

re-installin g, 4-26
removing, 4-25

—D—

Dagnostics

remote, 2-4
Data scope mode, 2-18
Default lin e s p e r inch , 2 -1 7
Dens ity o f prin t , 1- 6
Diagnostics

indicators, 2-7

knife failu re, 2-3

paper out, 2-3

power voltage low/high, 2-3

printhead over/under temperature, 2-3

receipt co v er o p e n, 2-3

runtime, 2-3

startup, 2-2
Dimensio n s, o f prin t er, 1 -4
Duty cy cle

limitation s, 1-7

Index-2

—E—

EEPROM

new, 2-2

Environmental conditions, 1-3

—I—

Indicators, 2-7

—K—

Knife

failure of, 2-3
re-installin g, 4-15
removing, 4-13

Knife hom e switch

re-installin g, 4-26
removing, 4-25

Knife option, 2-18

—L—

LED, 2-7

continuously flashes, 3-1
on continuously, 3-1

Level 0 diagnostics.

See

startup

diagnostics

Level 2 diagnostics.

See

runtime

diagnostics

Level 3 diagnostics.

See

remote

diagnostics

Light pipe

re-installin g, 4-18
removing, 4-16

—O—

Options PC board

re-installin g, 4-10

removing, 4-9

—P—

Paper

out, 2-3
Paper feed button

re-installin g, 4-18

removing, 4-16
Paper feed rod

re-installin g, 4-18

removing, 4-16
Paper jam, 3-2
Paper Low, 3-1, 3-2
Paper low sensor, 2-18
Paper low sensor/mount

re-installin g, 4-21

removing, 4-19
Paper out switch

re-installin g, 4-26

removing, 4-25
Platen

re-installin g, 4-12

removing, 4-11
Platen carrier assembly, 4-13
Power requirements, 1-2
Power sup p ly wa tt ag e, 2 -1 8
Print

light or spotty, 3-3

one side missing, 3-3

vertical column missing, 3-3
Print de nsit y

receipt, 1-6
printer

dimensions, 1-4

environmental conditions, 1-3

power requirements, 1-2

reliability , 1-1
Printer

Index-3

cleaning, 4-29
configuration, 2-11
cycles but does not print, 3-6
not functioning, 3-5
printing specifications, 1-5
service procedure map, 4-2

tools for service, 4-1
Printer con figuration, 2 -9
Printer emulations, 2-16
Printer s e ttin gs and functions, 2 -1 6
Printer stops printing , 3 -2
Printhead

cleaning, 4-29

over/under temperature, 2-3

print d e ns it y, 1-6
Printhead resistance, 2-21
Printing, continuous

limitations of, 1-7

—R—

Rear cover

open, 2-3

re-installin g, 4-12

removing, 4-11
Rear Door

re-installin g, 4-10

removing, 4-9
Receipt

not cut, 3-2
Re-installing

control PC board, 4-7

cover op en switch, 4-26

knife, 4-15

knife home switch, 4-26

light pipe, 4-18

options PC board, 4-10

paper feed button, 4-18

paper feed rod, 4-18

paper low se nsor/mount, 4 -21
paper out switch, 4-26
platen, 4-12
rear cover, 4-12
rear door, 4-10
reset rod, 4-18
rotating knife blade, 4-28

thermal me chanis m, 4-24
Reliability , 1-1
Remote diagnostics, 2-4
Removing

control board, 4-3

cover op en switch, 4-25

knife, 4-13

knife home switch, 4-25

light pipe, 4-16

options board, 4-9

paper feed button, 4-16

paper feed rod, 4-16

paper low se nsor/mount, 4 -19

paper out switch, 4-25

platen, 4-11

rear cover, 4-11

rear door, 4-9

reset rod, 4-16

rotating knife blade, 4-15, 4-27

thermal me chanis m, 4-22

top cover assembly, 4-16
Reset rod

re-installin g, 4-18

removing, 4-16
Rotating knife blade

re-installin g, 4-28

removing, 4-15, 4-27
RS-232C settings, 2-14
Runtime diagnostics, 2-3

Index-4

—S—

Service procedure map, 4-2
Settings and functions, 2-16
Specifications

printing, 1-5

Startup diagnostics, 2-2

—T—

Tallies.

See

remote diagnostics

Thermal me chanis m

re-installin g, 4-24
removing, 4-22

Tone, 2-7

indicating error, 3-2

two-tone beep, 3-2
Tools, 4-1
Top cover assembly

removing, 4-16

—V—

Voltage

low or high, 2-3

—W—

Weight, of printer, 1-4