Element RW-337D User manual

RW-337D Service Manual I Page 1of 61
RW-337D
Receipt Printer Service Manual

RW-337D Service Manual I Page 2of 61
Declaration
Information in this document is subject to change without notice. Element LTD. (hereinafter referred to as
“element”) reserves the right to improve product as new technology, components, software, and firmware become
available. If users need further data about this product or have any doubt about safety issues that might arise from
using it, please feel free to contact your dealer.
No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical,
for any purpose without the express written permission of element.
Copyright
Copyright © 2021 by Element.
Warning and Caution
Warning: Items shall be strictly followed to avoid damages to body and equipment.
Caution: Items with important information and prompts for operating the printer.

RW-337D Service Manual I Page 3of 61
Maintenance cautions
1) Follow the steps in this manual during maintenance;
2) Make sure that the printer and the computer are turned off before plugging/unplugging the communication
cable, changing print head or doing maintenance to the printer;
3) Be sure to protect it against electrostatic damage when maintaining print head and other electronic
components;
4) Time between turning on and turning off the printer should be no less than 20 seconds;
5) Do not print without paper and ribbon; otherwise you may damage the print bar and print head;
6) In order to ensure the stable work of each components and printer’s lifetime, you need to conduct a regular
maintenance monthly at least. The regular maintenance includes printer status check, printer dust cleaning
and part lubrication. If the printer has a larger workload, the maintenance cycle can be appropriately
shortened.

RW-337D Service Manual I Page 4of 61
Contents
1 Features and Specifications ...........................................................................................................................................1
1.1 Features..................................................................................................................................................................1
1.2 Technical Specifications..........................................................................................................................................1
2 Printer Overview ............................................................................................................................................................2
3 Main Control Board Description ....................................................................................................................................4
3.1 USB interface..........................................................................................................................................................4
3.1.1 Parameter .......................................................................................................................................................4
3.1.2 Interface signal................................................................................................................................................4
3.1.3 USB interface connection...............................................................................................................................4
3.2 Serial interface........................................................................................................................................................4
3.2.1 Parameter .......................................................................................................................................................4
3.2.2 Interface connection and signal function.......................................................................................................5
3.2.3 Serial connection ............................................................................................................................................5
3.3 Parallel interface.....................................................................................................................................................5
3.3.1 Parameter .......................................................................................................................................................5
3.3.2 Time Sequence of the Parallel Interface Module ..........................................................................................5
3.3.3 Interface signal................................................................................................................................................6
3.3.4 Parameter .......................................................................................................................................................7
3.3.5 Effect of printer’s status on parallel interface ...............................................................................................7
3.4 Ethernet interface...................................................................................................................................................7
3.4.1 Interface character .........................................................................................................................................7
3.4.2 Protocol supported.........................................................................................................................................7
3.4.3 Electrical character .........................................................................................................................................8
3.4.4 Frame type......................................................................................................................................................8
3.4.5 Interface signal................................................................................................................................................8
4 Disassembly and Assembly............................................................................................................................................9
4.1 Maintenance Tools .................................................................................................................................................9
4.2 Disassemble the printer .......................................................................................................................................10
4.2.1 Disassemble the printer cover......................................................................................................................10
4.2.2 Disassemble the main control board cover .................................................................................................13

RW-337D Service Manual I Page 5of 61
4.2.3 Disassemble the stationary blade cutter module........................................................................................14
4.2.4 Disassemble the non-retraction platen roller module ................................................................................15
4.2.5 Disassemble the paper cabinet module.......................................................................................................17
4.2.6 Disassemble the print module......................................................................................................................20
4.3 Assemble the printer............................................................................................................................................24
5 Printer maintenance ....................................................................................................................................................25
5.1 Main part replacement ........................................................................................................................................25
5.1.1 Print head replacement................................................................................................................................25
5.1.2 Cutter replacement ......................................................................................................................................26
5.1.3 Main control board replacement.................................................................................................................28
5.1.4 Paper feed motor replacement....................................................................................................................28
5.1.5 CR motor replacement .................................................................................................................................29
5.1.6 Upper mark sensor replacement..................................................................................................................30
5.1.7 Lower mark sensor replacement..................................................................................................................31
5.1.8 HP sensor replacement.................................................................................................................................32
5.1.9 Paper sensor replacement............................................................................................................................32
5.2 Printer adjustment ...............................................................................................................................................33
5.2.1 Print spacing adjustment..............................................................................................................................33
5.2.2 Tighten transmission belt of carriage...........................................................................................................34
6 Error Types and Processing..........................................................................................................................................35
7 Troubleshooting ...........................................................................................................................................................36
7.1 Abnormal print effect...........................................................................................................................................36
7.2 Abnormal paper detection...................................................................................................................................36
7.3 Printing with noise................................................................................................................................................36
7.4 Abnormal ribbon action .......................................................................................................................................37
7.5 Abnormal cutter action ........................................................................................................................................37
7.6 Printer doesn’t work.............................................................................................................................................38
7.7 Problem during the printing process ...................................................................................................................38
Appendix .........................................................................................................................................................................39
Appendix 1 Hexadecimal Dump Mode.......................................................................................................................39
Appendix 2 Command list ..........................................................................................................................................40
Appendix 3 EEPROM setting table .............................................................................................................................42
Appendix 4 Spare part list ..........................................................................................................................................43

RW-337D Service Manual I Page 6of 61
Appendix 5 Exploded drawing of the printer.............................................................................................................46
Appendix 6 Part list.....................................................................................................................................................49
Appendix 7 Outline drawing.......................................................................................................................................53
Appendix 8 Main board layout...................................................................................................................................54
Appendix 9 Lubrication...............................................................................................................................................55

RW-337D Service Manual I Page 1of 61
1 Features and Specifications
1.1 Features
The RW-337D is a 9-pin serial impact dot matrix receipt printer offering high quality, high speed, and stable
performance. It is widely used in real-time printing on-site, such as POS system, kitchen and finance applications.
The RW-337D can be connected with other devices via USB, parallel, serial and Ethernet interface, and it provides
drivers and applications under 2000/2003/XP/Vista.
1.2 Technical Specifications
Item
Specifications
Print mode
9-pin serial impact dot matrix
Print speed
Max. 4.7LPS (400 dots/line)
Print width
Max. 400(half dots)/200(full dots)
Paper
Paper type
Continuous paper or marked paper
Single layer
Paper width: 80±0.5mm,76±0.5mm,69.5±0.5mm,57.5±0.5mm;
Paper thickness: 0.06—0.085mm
Multi-layer paper
(1 original+1 copies)
Paper width: 80±0.5mm,76±0.5mm,69.5±0.5mm,57.5±0.5mm;
Paper thickness: 0.05—0.08mm, total thickness≤0.14 mm
Character
Character type
Font A: 9×9 Font B: 7×9 Chinese: 16×16
Characters/line (Default)
76mm
69.5mm
57.5mm
Font A
33 CPL
30 CPL
25 CPL
Font B
40 CPL
36 CPL
30 CPL
Chinese
22 CPL
20 CPL
16 CPL
Character size (Default)
Font A: 1.6×3.1mm Font B: 1.2×3.1mm Chinese: 2.7×2.9mm
Characters/inch (Default)
Font A: 13.3CPI Font B: 16CPI Chinese: 8.9CPI
Data
buffer
Receiving buffer
64KB/8KB/40Byte
NV image data
128KB
NV user data
8KB
Ribbon specification
ERC-38 ribbon cartridge
Ribbon lifetime
ERC-38(P)
4,000,000 characters
ERC-38(B)
3,000,000 characters
ERC-38(B/R)
Black: 1,500,000 characters
Red: 750,000 characters
Communication interface
USB / IEEE1284/RS-232/Ethernet /(optional)
Cash drawer connector
Can control 1～2 cash drawers
Power supply
AC100-240V~1.0A Max 50-60Hz
Reliability
Printing Mechanism
10,000,000 lines
Print head
150,000,000 characters
Cutter
800,000 cuts(paper thickness:0.080mm, standard testing condition)
Operating temperature and humidity
5～45℃,20～90%RH (40℃)
Storage temperature and humidity
-40～60℃,20%～93%RH (40℃)
Dimensions
160(W)×245(D)×154(H)
Weight
3.0kg

RW-337D Service Manual I Page 2of 61
2 Printer Overview
The RW-337D printer consists of the following parts:
Pinter mechanism part, NDLF main control board, expanded interface board.
Main control board unit block diagram is shown as below:
CPU
FLASH
Communication interface
module
Communication interface
module STY_HHEAD
Print head drive
circuit
Power
input
interface
COV2 COV1 BM2 PE BM1
PLOW
1
PLOW
2HP
CN500
MOTO1 KEY_LED
1
MOTO2
Power
switch
Cutter drive
circuit
Motor drive
circuit
Printer
mechanism
Communication
interface module
Host
Host
Communication
interface module
Main Control Board Unit Block Diagram

RW-337D Service Manual I Page 3of 61
Position of all the sockets in the main control board

RW-337D Service Manual I Page 4of 61
3 Main Control Board Description
RW-337D can be connected to another device with USB, serial, parallel, Ethernet or WIFI interface.
3.1 USB interface
3.1.1 Parameter
➢Data transfer: Supports USB1.1 Protocol
➢Connector: USB B type standard socket
3.1.2 Interface signal
The printer built-in USB interface supports USB1.1 protocol, of which the outlet is USB A type.
Interface signal is defined as below:
3.1.3 USB interface connection
Host Printer
VBUS..................................…VBUS
DATA- ................................…DATA-
DATA+................................... DATA+
GND .......................................GND
Caution:
The vertical USB interface cannot be used when set the receiving buffer to 40Bytes.
3.2 Serial interface
3.2.1 Parameter
➢Data transmission: Asynchronous serial communicate
➢Handshaking: DTR/DSR or XON/XOFF
➢Voltage: MARK = -3 to -15V: Logic "1"/ OFF
SPACE = +3 to +15V: Logic "0"/ ON
➢Baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600 bps
[bps: bits per second]
➢Data bit: 7 bit or 8 bit
➢Parity bits: No
➢Stop bit: 1 bit or 2 bit
➢Connector: D-SUB 25PIN hole socket
Caution:
Handshaking, baud rate, data bit and stop bit can be set by EEPROM and feed button.
Pin
Signal name
Function
1
VBUS
+5V
2
DATA-
Data-
3
DATA+
Data+
4
GND
Ground