SHARP PR-45M Service Manual

SERVICE MANUAL

THERMAL PRINTER

MODEL PR-45M

PR-45M : MANUAL CUTTER

CONTENTS

CHAPTER 1. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

CHAPTER 2. OUTLINE OF DRIVING CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . 3

CHAPTER 3. HANDLING THE PRINTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

CHAPTER 4. MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

CHAPTER 5. TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

CHAPTER 6. DISASSEMBLY AND ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . 12

CHAPTER 7. PWB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

PARTS GUIDE (Ki-OB2359BHZZ)
APPLICATION MODEL (As of Dec.)
ER-A455X Series, ER-A450/A450S ("V" Version), ER-A450T ("U" and "A" Version)

This document has been published to be used

SHARP CORPORATION

for after sales service only.
The contents are subject to change without notice.

CHAPTER 1. SPECIFICATIONS

2. Specifications

1) Printer

Item Description
No. of station 2: Receipt and Journal
Validation No
Printing system Line thermal
No. of dot Receipt: 288 dots

Journal 288 dots

Dot pitch Horizontal: 0.125 mm

Vertical: 0.125 mm
Font 10 dots (W) × 24 dots (H)
Printing capacity Receipt: Max. 24 characters

Journal: Max. 24 characters
Character size 1.25 mm (W) × 3.0 mm (H): At 10 × 24 dots
Print pitch Column distance: 1.5 mm

Row distance: 3.75 mm
Paper feed speed Approximate 50 mm/s
Reliability Mechanism: MCBF 5 million lines

Thermal head: 5 million pulses
Paper end sensor Yes (Receipt and Journal)
Cutter Manual
Paper near end sensor No
Printing area

(4.5) (4)

0.125

288dots

(36)

44.5 ±0.5

3.0

(4)

(4.5)

UNIT: mm

Item Description
Printing format 12 × 24 font

1.5 (12dots) 1.5 (12dots)

0.125

0.125

3.0 (24dots)

3.75 (30dots)

2) Tools required for maintenance and repair

For NAME Remarks

Mainrenance Cleaning brush

Cotton swab
Clean cloth
Alcoholic solvent Ethanol, Methanol, IPA
Cleaning brush

Repair (+) Screwdriver

(-) Screwdriver
Tweezers
Pliers
Nippers
Soldering iron
ET holder
Grease : G-36 00BB703600001
Cleaning brush
Cotton swab
Clean cloth
Alcoholic solvent Ethanol, Methanol, IPA
Cleaning brush

3.75 (30dots)

UNIT: mm

CHAPTER 2. OUTLINE OF DRIVING
CIRCUIT

1. Block diagram & Connection diagram

1) Block diagram

CON2(9P)

FOR ECR PWB

Signal

GND

Pin

No.

2
5
8

Pin

No.

PWB UNIT

CON1(40P)

Pin
No.

15

Signal

VH
/LAT
GND

Signal

CON3(9P)

TM

Signal

CON7(6P)

CON5(2P)

Non-paper

detection

sensor(R)

Pin

No.

3
6
9

Pin
No.

Pin
No.

16

Dout
/STB3
GND

6

HEAD UP

SENSOR

Signal

VDD
(+5V)

Signal

Signal

MOTOR

CON6(6P)

J

6

MOTOR

CON4(4P)
Non-paper

detection

sensor(J)

FOR THERMAL HEAD FOR THERMAL HEAD

2) Connector table

Connect to the ECR PWB
CON1: <For ECR PWB>

PinNo. Signal

1VHIN 2NC 3NC 4NC
5 VJCOM 6 VJPFD 7 /JPFA 8 /JPFB
9 /JPFC 10 /JPFD 11 /JPES 12 GND

GND

13
17 /STB4 18 /STB3 19 Din 20 VH

21 VH 22 VH 23 VH 24 Dout
25 CLK 26 /LAT 27 /STB2 28 /STB1
29 GND 30 GND 31 GND 32 /RPES
33 VRCOM 34 VRCOM 35 /RPFA 36 /RPFB
37 /RPFC 38 /RPFD 39 PHUPS 40 VHOUT

CON2: <For Thermal head connector A>

Pin
No.

1VH
4 CLK
7 /STB1

CON3: <For Thermal head connector B>

Pin
No.

1GND 2GND 3NC
4 TM 5 VDD (+5V) 6 /STB4
7/STB3 8Din 9VH

10 VH

CON4: Not used

Pin
No.

14

Signal

Signal

CON5: <For Head up detector>

Pin
No.

Signal

Pin
No.

Signal

1 PHUPS 2 GND-L

CON6: <For Journal paper feed motor>

Pin
No.

Signal

Pin
No.

Signal

Pin
No.

Signal

1VJCOM 2VJCOM 3/JPFA
4/JPFB 5/JPFC 6/JPFD

CON7: <For Receipt paper feed motor>

R

Pin
No.

Signal

Pin
No.

Signal

Pin
No.

Signal

1 VRCOM 2 VRCOM 3 /RPFA
4/RPFB 5/RPFC 6/RPFD

3) Thermal head block diagram

DOT #864

8, 9

VH

DI

TM

Connector B

1, 2

5

6

7

4

3

4 3

THERMISTOR

LATCH REGISTER

SHIFT REGISTER

The STB terminal is pulled
in the IC.

GND

STB4

STB3

VDD

Thermal head connector A

Pin No. Signal Description

1

VH Head application voltage

2
3 D out Data output signal
4 CLK Clock signal
5 /LAT Latch Signal
6 /STB2 Strobe Signal 2
7 /STB1 Strobe Signal 1
8

GND GND

9

Thermal head connector B

Pin No. Signal Description

1

GND GND

2
3 TM Thermistor detecting signal
4VDD +5V
5 /STB4 Strobe Signal 4
6 /STB3 Strobe Signal 3
7 D in Data input signal
8

VH Head application voltage

9

Print data which has been entered through Din signal synchronization
with the CLOCK signal is stored in /LAT according to the timing (864
dots) of the /LATCH signal. Stored print data is output by the
/STROBE1, /STROBE2, /STROBE3, and /STROBE4 signals to ener­gize the heating element. The print data (864 dots) is divided by four
STROBE signals into the following four parts before being output.

DOT #1

12

1, 2

8, 9

7

6

5

3
4

Connector A

VH

GND

STB1

STB2

LAT

DO
CLK

STROBE No. DOT No. Dots/ Strobe Note

/STROBE4 577 ∼ 864 288 Excluding dots No.1 ∼ 88,
/STROBE3 433 ∼ 576 144
/STROBE2 289 ∼ 432 144
/STROBE1 1 ∼ 288 288

377 ∼ 488 and 777 ∼ 864

4) Motor block diagram

stepping motor
/RPFA, /JPFA
/RPFB, /JPFB
/RPFC, /JPFC
/RPFD, /JPFD

VRCOM, VJCOM
VRCOM, VJCOM

<JOURNAL MOTOR>

PIN

SIGNAL

No.

<RECEIPT MOTOR>

PIN
No.

The paper feed motors are stepping motors with 4-phase driving
coils. The motors are driven by switching over the driving coils.

<MOTOR DRIVE SEQUENCE> ON: Energized/OFF: Not energized
JOURNAL MOTOR

STEP No. PHASE A PHASE B PHASE C PHASE D

NAME

1

VJCOM COMMON voltage

2
3/JPFA

4/JPFB

5/JPFC

6/JPFD

SIGNAL

NAME

1

VRCOM COMMON voltage

2
3/RPFA

4/RPFB

5/RPFC

6/RPFD

1ONOFFOFFON
2ONOFFONOFF
3 OFF ON ON OFF
4OFFONOFFON

JOURNAL-side paper feed motor phase A
driving signal

JOURNAL-side paper feed motor phase B
driving signal

JOURNAL-side paper feed motor phase C
driving signal

JOURNAL-side paper feed motor phase D
driving signal

RECEIPT-side paper feed motor phase A
driving signal

RECEIPT-side paper feed motor phase B
driving signal

RECEIPT-side paper feed motor phase C
driving signal

RECEIPT-side paper feed motor phase D
driving signal

DESCRIPTION

DESCRIPTION

C

D

AB

M

5) End sensor block diagram

reflex photo sensor

+5V

0.1µF

/RPES, /JPES

GND-L

SIGNAL NAME DESCRIPTION

+5V +5V

/RPES Receipt paper end sensor detecting signal

/JPES Journal paper end sensor detecting signal
GNDL GND

The photo diode on the PWB detects the presence/absence of the
paper passing under the journal and receipt platens.

3

2

4

1

39KΩ 220Ω

6) Head up sensor

micro switch

PHUPS

GND-L

SIGNAL NAME DESCRIPTION

PHUPS Head-up detecting signal

GNDL GND

The micro switch at the left side of the printer detects the head-up
state.

ON: Head-down
OFF: Head-up

RECEIPT MOTOR

STEP No. PHASE A PHASE B PHASE C PHASE D

1ONOFFONOFF
2ONOFFOFFON
3OFFONOFFON
4 OFF ON ON OFF

CHAPTER 3. HANDLING THE
PRINTER

1 Special Handling Considerations

(1) When transporting the printer

•

When transporting the printer, the head up le ver should be raised

in the

B: Head up position so that the head does not contact the

platen rollers.
Failure to do so will may result in pear the printer performance.

• When the printer is carried, it should not be held at the connectors,

the lead wires, paper take-up frame, etc.

• When carrying the printer, never allow large impacts to occur, such

as by dropping, collision, etc.

• When carrying the printer, hold the frame with both hands, as

shown in the figure below.

:Head-up position

The head is not in contact with the platen roller.
When the printer is out of service for a long time or when it

is to be transported.

The illustration shows the state when the PT-cover is removed
for explanation purposes only.

Head

Platen roller

Fig. Carrying the printer unit

• When transporting the printer, pack it using anti-static packaging.

Do not touch the thermal head and the surface of the PWB. When
handling the printer, properly ground yourself.

Head up lever position

: Close position

The head is in contact with the platen roller
The printer operates and feeds the paper.

The illustration shows the state when the PT-cover is removed
for explanation purposes only.

(In contact)

Head

Platen roller

Head Up Lever

Head-up position

Fig.

H-Spring

: Cleaning position

When the head and platen roller are to be cleaned.
Do not leave the head-up lever in this position; Failure to do

so might result in a deformed H-spring, thus leading to poor
print or paper feed quality.

The illustration shows the state when the PT-cover is removed
for explanation purposes only.

Head

Platen roller

Head Up Lever

Fig.

Close position

H-Spring

Head Up Lever

Fig.

H-Spring

Cleaning position

(2) When storing the printer

Printer

• When stori ng the printer, make sure to raise the head up lever

in the
position or

: Head up position. Never store it with the : Close

: Cleaning position.

• Avoid st oring the printer in areas with a lot of dust, direct sun-

light, or high humidity.

• I f the printer is stored for an extended period, put it in a anti-

static bag and store it in a dry place.

• The t hermal paper should not be left for an extended period

(more than two weeks at normal temperature) held between
the platen roller and the head (

: Close position).

• Do not leave the printer in the : Checking position for more

than 2 days.

Paper (thermal paper)

• Since t hermal paper gradually darkens from about 70°C, pay

attention to heat, humidity, sun light, etc., regardless whether or
not the paper has been printed on.

• Avoid high temperature and high humidity areas.

• Avoid direct sun light.

(When thermal paper is left near the window in direct sun
light, the base color may change and discoloring may take
place.)

(3) When using the printer

Printer

• Since t he printer contains a thermal head, permanent magnets

(motor) and micro switches, avoid using it in areas with a lot of
iron powder, dust, etc.

• Never operate with no paper loaded.

• Never pul l out the paper (forward or backward) with the head

head against the platen rollers.

• Do not touch the head heating elements and driver Ics, espe-

cially with hard or metal objects.

• Duri ng printing and just after printing completes (for about 15

minutes), the area around the head and the motor surface are
very hot. Never directly touch them with your hand.

• Operate the head up lever only when required.

Never touch the surface of the head heating elements.
(Dirt may stick to the heating elements and affect the printing.)

• Never leave the printer with the platen rollers and the head

directly touching (
Do not leave the head-up lever in the
more than 2 days.
(When the printer is left for a while, make sure to raise the head
up lever in the ➡

: Close position).

: Cleaning position for

: direction in Fig. Loading paper.)

• Since el ectronic parts are used in the print head, never touch

the thermal head with your bare hand.
Before handling the printer, execute proper body grounding
procedures to avoid static electricity.

Paper (thermal paper)

• Use only the specified thermal paper.

(Thermal paper with a rough surface may result in poor printer
quality and shorten the print head life.)

(4) When mounting the printer

•

Make sure the power is turned OFF before installing the printer to
an ECR.

• When att aching the printer to your product, avoid areas with a lot

of iron powder, dust, etc.

2. Loading the Paper (insertion and
removal)

Use only the paper specified in the specification sheet issued by our
company.

(1) Loading paper

Load paper following the procedure below.

Cut the edge of the paper as shown in the figure below.

Good WrongGood Wrong

Fig. Shape of the cut paper edge

Good Bad

Fig. Paper setting state

Recording paper

B

C

Fig. Loading paper

Turn the ECR ON.
Make sure the head-up lever in the (Close) position.
Insert the paper through the paper inlet.
The paper is automatically loaded into the printer by the auto

loading mechanism and the leading edge of the paper roll is deliv­ered a little from the paper outlet.

If there is slackness in the paper or paper is loaded slantly, set the
head up lever in the head up position
position.

If the length of the paper delivered from the outlet is insufficient,
feed the paper properly with the key board of the ECR.

(Notes) If paper is fed without following the above procedure, it

could cause improper paper feeding and jamming.

Head up lever

A

and adjust the paper

(2) Unloading the paper

The paper can be unloaded in two ways.

Move the head up lever toward : Head up position and then pull
the paper out by hand in the forward direction (feeding direction)
or in the reverse direction.

Operate the paper feed mechanism to discharge the paper from
the printer. Move the head up lever to the head up position
remove the paper toward the front.

• Operations other than those listed above could cause im-

(Notes)

proper paper feeding and jamming, and could cause
breaking of the head heating elements.

and

• Never pull the paper out without using the head up lever,

regardless of the direction, forward or reverse.

(3) Removing paper after a paper jam

If a paper jam occurs, follow the procedure below.

Put the head-up lever in the Cleaning position to widen the
spacing between the head and platen rollers so that you can
easily check for a paper jam.

Remove a jammed paper by hand.
Return the head-up lever in the Close position.

When a tool such as tweezers, is used to remove paper chips, take
care not to touch the heating elements of the head with the tool.
Since the head is still hot just after the operation printing is stopped,
wait a while for the head to cool down.

CHAPTER 4. MAINTENANCE

2. Inspection

The maintenance and inspection items for the printer are dividend
into 2 types. One is "Daily checks" for the person who uses the
printer, and the other is "Periodic checks" for someone with more
technical knowledge. Maintenance and inspections should be carried
out by properly qualified personnel.

(1) Daily checks

Check that the printer is used properly and kept in the good repair.

Daily check items

The specified paper is being used.
The paper has not become discolored.
Check print quality and if significant deterioration is found, clean

the head heating elements.

<Head cleaning method>

1) Place the head-up lever in the
is securely lock ed .

2) Wipe the heating element of the head and platen rollers clean with
a soft cloth or cotton pledget moistened with alcoholic solvent
(ethanol, methanol or IPA: isopropyl alcohol).

3) After making sure the alcoholic solvent has thoroughly evapo­rated, undo the head-up lever and platen rollers in t he
position.

If paper dust is attached to the platen roller surface, the paper
feeding power is reduced. Be sure to clean the platen roller sur­face when cleaning the head.

The illustration shows the state when the PT-cover is removed for
explanation purposes only.

: Cleaning position. Make sure it

Close

Thermal head unit

To maintain proper performance of the printer for a long period of
time and to prevent trouble, carry out the maintenance and manage­ment procedures as follows.

1. Cleaning

• Removing stains

Wipe dirt off the head and platen rollers with a clean cloth satu­rated with an alcoholic solvent (ethanol, met hanol, IPA: Isopropyl
alcohol).
For cleaning the head part, refer to daily checks.

(Notes) Never use thinner, benzine, trichlene or ketone group sol-

vents, since they may damage or deteriorate rubber and
plastic parts.

• Removing dust and fuzz

Cleaning by suction (with a vacuum cleaner) is desirable.
Suck up all the dust and fuzz.

(Notes) Check lubrication at various points after cleaning, and lubri-

cate with oil at the specified locations.

Cotton swab

Fig. Head and Platen roller cleaning

Platen roller