Star Micronics LC-8521 User manual

DOT MATRIX PRINTER
LC-8521
TECHNICAL MANUAL
[THIRDEDITION]

NOTICE
•Allrightsreserved.Reproductionofanypartofthismanualinany
form whatsoever, without STAR’s express permission is forbid-
den.
•The contents of this manual are subject to change without notice.
•All efforts have been made to ensure the accuracy of the contents
of this manual at the time of going to press. However, should any
errors be detected, STAR would greatly appreciate being in-
formed of them.
•The above notwithstanding, STAR can assume no responsibility
for any errors in this manual.
© Copyright 1997 Star Micronics Co.,Ltd.

INTRODUCTION
This manual describes the LC-8521 dot matrix printer.
Itisdesignedforuseasareferenceforperiodicinspectionsandmaintenanceprocedurestobeexecutedby
servicepersonnel.Itisnotintendedforthegeneraluser.Usersofthismanualshouldhaveabasicknowledge
and understanding of the English language.
•This manual is divided into the following sections:
Chapter 1 General Specifications
Chapter 2 Theory of Operation
Chapter 3 Adjustments
Chapter 4 Parts Replacement
Chapter 5 Maintenance and Lubrication
Chapter 6 Troubleshooting
Chapter 7 Parts List
•First edition : Mar. 1997
Second edition : Aug. 1997
Third edition : Nov. 1998
1
2
3
4
5
6
7

CHAPTER 1
GENERAL SPECIFICATIONS
1. General Spaecifications........................................................................................3
2. External Appearance and Composition ..............................................................5
3. Control Panel .........................................................................................................7
3-1. Switch Combination Functions ............................................................................. 7
3-2. EDS Mode Settings................................................................................................. 8
4. Parallel Interface..................................................................................................10
4-1. General Specifications ......................................................................................... 10
4-2. Connector Signals ................................................................................................ 10
5. Serial Interface.....................................................................................................11
5-1. General Specifications ......................................................................................... 11
5-2. Connector Signals and Functional Descriptions............................................... 11
6. Serial Interface - SPC-8K (Option) .....................................................................12
6-1. General Specifications ......................................................................................... 12
6-2. Connector Signals and Functional Descriptions............................................... 12
6-3. DIP Switch Settings .............................................................................................. 13
7. EE-PROM Mode ...................................................................................................14
7-1. Outline ................................................................................................................... 14
7-2. Explanation of Special Control Codes................................................................ 14
7-3. EE-PROM Map....................................................................................................... 15
7-4. Rewriting the EE-PROM ....................................................................................... 19
1

– 2 –

– 3 –
Printing System Serial Impact Dot-Matrix
Printing Speed Pitch HS-Draft (cps/dpi) Draft (cps/dpi) LQ (cps/dpi)
Pica (10 cpi) 400/80H 300/120H 100/360H
Elite (12 cpi) 360/120H 120/360H
Semi-condensed (15 cpi (S)) 450/120H 150/360H
Semi-condensed (15 cpi (I)) 212/240H 150/360H
Condensed pica (17 cpi) 242/240H 171/360H
Condensed elite (20 cpi) 283/240H 200/360H
24 cpi (I) 340/240H 240/360H
H: half-dot
(S): Standard mode only
(I): IBM mode only
Print Direction Draft: Bi-directional logic seeking
LQ: Bi-directional logic seeking
Bit-Image: Uni-directional/bi-directional logic seeking (selectable)
Print Head Number of pins: 24
Life: 200 million dots/pin (adjustment lever position 1 to 3)
100 million dots/pin (adjustment lever position 4 to 8)
Line Spacing 1/6″, 1/8″
7/60″, 7/72″, n/72″, n/180″, n/216″, n/360″: software
Character Matrix Pitch HS-Draft Draft LQ
Pica (10 cpi) 24×7Η 24 ×9H 24 ×31H
Elite (12 cpi) 24 ×9H 24 ×27H
Semi-condensed (15 cpi(S)) 16 ×7H 16 ×21H
Semi-condensed (15 cpi(I)) 24 ×9H 24 ×16H
Condensed pica (17 cpi) 24 ×9H 24 ×16H
Condensed elite (20 cpi) 24 ×9H 24 ×16H
24 cpi (I) 24 ×9H 24 ×14H
H: half-dot
(S): Standard mode only
(I): IBM mode only
Environment Operating temperature: 41˚F to 95˚F (5˚C to 35˚C)
Storage temperature: -22˚F to 149˚F (-30˚C to 65˚C)
Operating humidity: 30% to 80% (noncondensing)
Storage humidity: 20% to 90% (noncondensing)
Paper Cut-sheet
Paper width: 2″to 16.5″/ 51 to 420 mm
Paper length: 2.75″to 14″/ 70 to 356 mm
Paper weight (1-ply): 14 to 42 lbs / 52 to 156 g/m2/ 45 to 135 kg
Multi-part: 11 to 14 lbs / 40 to 52 g/m2/ 34 to 45 kg; pressure
sensitive paper
Total thickness: 0.014″/0.35mm
Copies: Original + 4
1. General Specifications

– 4 –
Fanfold
Paper width: 3″to 16″/ 76 to 406mm
Paper length 6″/ 152mm(min.)
Paper weight (1-ply): 14 to 22 lbs / 52 to 82 g/m2/ 45 to 70 kg
Multi-part: 11 to 14 lbs / 40 to 52 g/m2/ 34 to 45 kg; pressure
sensitive paper
Total thickness: 0.014″/ 0.35mm
Copies: Original + 4
Labels
Backing sheet: 3″to 16″/ 76 to 406mm
Thickness:
Backing sheet 0.0028″to 0.0035″/ 0.07 to 0.09mm
Total thickness 0.0075″/ 0.19mm max.
Envelope
#10 9.4″×4.1″/ 240 ×104mm
#6 6.5″×3.6″/ 166 ×92mm
Emulation Standard Mode: EPSON ESC/P (24-pin)
NEC Graphic Compatible
IBM Mode: Proprinter XL24E
Interface Standard: Centronics parallel
RS-232C serial
Ribbon Type On-carriage, dedicated
Monochrome: Black only
LZ24HD (Standard)
Ribbon Life LZ24HD: 4million characters (ASCII Draft)
Power Supply 110V AC +20%/-18%, 230V AC +14%/-13%; 50/60Hz (depending on country of
purchase)
Power Consumption 17W during stand-by
63W during ASCII draft printing
Options SPC-8K Serial-To-Parallel Converter
CT-15HA Push Tractor Unit
Fig. 1-1 External dimensions
650mm
240mm
333mm
25.6"
13.1"
9.5"
Weight: 28.7lbs/13kg

– 5 –
2. External Appearance and Composition
Fig. 1-3 Rear view of the Printer
Fig. 1-2 Front view of the Printer
Front cover
Adjustment lever
Paper guide
Release lever
Power switch
Document table
Control panel Platen knob
Parallel Interface
connector
Serial Interface
connector

– 6 –
Tractor
Carriage
Paper Feed Motor
Printer Mechanism
Carriage Motor
Ribbon Holder
Control Panel Board
Main Logic Board
Power Supply Unit
Fig. 1-4 Front cover removed
Ribbon Cartridge
Print Head
Platen
Gap Adjustment assy
Paper Feed Roller
Fig. 1-5 Diagram of internal layout

– 7 –
3. Control Panel
3-1. Switch Combination Functions
Font & Pitch Lock Hex Dump Mode
EDS-2 Mode
EDS-1 Mode
Dot-Adjustment Mode
On-LineLine FeedPitch Selection Set/Eject/ParkFont Selection
Off-LineTear offQuiet Mode
Forward
Panel Macro
Set TOF
Form Feed
Buffer Clear & All Reset OFF-LINE
Exit
PrintSwitchBank
POWER-ON
Exit
NextRightLeft
EDS MODE
DOT-ADJUSTMENT MODE
Short TestLong TestMulti-part ModeFont Lock
ON-LINE
Pitch Lock
On/Off
Micro FeedBack ward
Auto Loading Position Change Mode
Factory settings
Cancel
ForwardPaper Loading Back ward
Save
Set
AUTO LOADING POSITION CHANGE MODE
HS-DRAFT BANK SW
D 4
E 5
F 6
A 1
B 2
C 3
10 CPI POWER
15 CPI
COND
PROP
12 CPI
DRAFT
ROMAN
SANSERIF
COURIER
PRESTIGE
ORATOR
FONT
BANK SW ON/OFF
EDS PRINT EXIT
PITCH ON LINE
PARK
SET/EJECT PAPER FEED
Aging mode
Test
EEPROM Data Initialize

– 8 –
3-2. EDS Mode Settings
(EDS - 1)
Bank Switch Function ON OFF
A 1 Emulation *Standard / EPSON IBM
2 Character Table (CT) Standard / EPSON mode *Graphics Italics
IBM mode IBM #2 IBM #1
3 RAM usage *Input Buffer Download Buffer
4 Paper Out Detector *Enabled Disabled
5,6 Multi-part mode
* Auto selectable ON ON Normal mode ON OFF
Multi-part mode OFF ON
B 1 Graphics Direction *Bi-directional Uni-directional
2 Auto Tear-off (Long) *Disabled Enabled
3 Line Spacing *1/6″1/8″
4 Auto LF with CR *Disabled Enabled
5 Zero Style *Normal Slashed
6 Strobe Timing *Normal Reveres
C 1, 2 Print Mode
* LQ ON ON HS-Draft ON OFF
Draft OFF ON
3,4,5 Print Pitch
* 10cpi ON ON ON 17cpi OFF OFF ON
12cpi OFF ON ON 20cpi ON ON OFF
15cpi ON OFF ON Proportional OFF ON OFF
6 Quiet *Disabled Enabled
D 1,2,3,4 Page Length
*11″/Letter ON ON ON ON 14″/Legal OFF ON OFF ON
8″OFF ON ON ON 10.5″/Executive ON OFF OFF ON
11.7″/A4 ON OFF ON ON 7.25″/Executive OFF OFF OFF ON
12″OFF OFF ON ON 3.5″ON ON ON OFF
8.5″/Letter ON ON OFF ON 5.5″OFF ON ON OFF
5 Eject direction for cut sheet *Front Rear
6 Skew sensor for cut sheet *Disabled Enabled
E 1, 2, 3, 4, 5, 6 Code Page (CT=Graphics, IBM #1, #2)
* #437 ON ON ON ON ON ON #869 OFF OFF ON ON OFF ON
#850 OFF ON ON ON ON ON #928 ON ON OFF ON OFF ON
#860 ON OFF ON ON ON ON #2001 OFF ON OFF ON OFF ON
#861 OFF OFF ON ON ON ON #772 ON OFF OFF ON OFF ON
#863 ON ON OFF ON ON ON #774 OFF OFF OFF ON OFF ON
#865 OFF ON OFF ON ON ON #3001 ON ON ON OFF OFF ON
#866 ON OFF OFF ON ON ON #3002 OFF ON ON OFF OFF ON
#3840 OFF OFF OFF ON ON ON #3011 ON OFF ON OFF OFF ON
#3841 ON ON ON OFF ON ON #3012 OFF OFF ON OFF OFF ON
#3843 OFF ON ON OFF ON ON #3021 ON ON OFF OFF OFF ON
#3844 ON OFF ON OFF ON ON #3031 OFF ON OFF OFF OFF ON
#3845 OFF OFF ON OFF ON ON #3041 ON OFF OFF OFF OFF ON
#3846 ON ON OFF OFF ON ON #3850 OFF OFF OFF OFF OFF ON
#3847 OFF ON OFF OFF ON ON #3860 ON ON ON ON ON OFF
#3848 ON OFF OFF OFF ON ON #3861 OFF ON ON ON ON OFF
#852 OFF OFF OFF OFF ON ON #3863 ON OFF ON ON ON OFF
#1001 ON ON ON ON OFF ON #3864 OFF OFF ON ON ON OFF
#737 OFF ON ON ON OFF ON #3865 ON ON OFF ON ON OFF
#851 ON OFF ON ON OFF ON
International Character Set (CT=Italics)
U.S.A. ON ON ON ON ON ON Japan ON ON ON OFF ON ON
France OFF ON ON ON ON ON Norway OFF ON ON OFF ON ON
Germany ON OFF ON ON ON ON Denmark-2 ON OFF ON OFF ON ON
England OFF OFF ON ON ON ON Spain-2 OFF OFF ON OFF ON ON
Denmark-1 ON ON OFF ON ON ON Latin America ON ON OFF OFF ON ON
Sweden OFF ON OFF ON ON ON Korea OFF ON OFF OFF ON ON
Italy ON OFF OFF ON ON ON Ireland ON OFF OFF OFF ON ON
Spain-1 OFF OFF OFF ON ON ON Legal OFF OFF OFF OFF ON ON
F 1, 2, 3, 4, 5, 6 LQ Font Selection
* Roman ON ON ON ON ON ON Prestige OFF OFF ON ON ON ON
Sanserif OFF ON ON ON ON ON OCR B OFF ON OFF ON ON ON
Courier ON OFF ON ON ON ON Orator OFF OFF OFF ON ON ON
*: Default setting

– 9 –
(EDS - 2)
Bank Switch Function ON OFF
A 1 Data bits *8 bits 7 bits
2 Parity check *Disabled Enabled
3 Parity *Odd Even
4 Protocol *DTR XON / XOFF
5 (Not used) -------- --------
6 (Not used) -------- --------
B 1 Baud rate
2
3
4 (Not used) -------- --------
5,6 Waiting period for Paper loading
* 2.0 ON ON 1.0 ON OFF
1.5 OFF ON 0.5 OFF OFF
C 1 Top margin for cut sheet *1/6″0″
2 Top margin for Fanfold paper (Rear) *1/6″0″
3 Top margin for Fanfold paper (Front) *1/6″0″
4 Bottom margin for Cut sheet *1/6″0″
5 Bottom margin for Fanfold paper (Rear) *1/6″0″
6 Bottom margin for Fanfold paper (Front) *1/6″0″
*: Default settings
----- 19200 *9600 4800 2400 1200 600 300
1 ON OFF ON OFF ON OFF ON OFF
2 ON ON OFF OFF ON ON OFF OFF
3 ON ON ON ON OFF OFF OFF OFF

– 10 –
ACK
Data
STROBE
(EDS B-6 : ON)
STROBE
(EDS B-6 : OFF)
BUSY
4µs
t : More than 0.5µs
4µs
tttt
4. Parallel Interface
4-1. General Specifications
Item Specifications
Interface Centronics-compatible
Synchronization System Via externally supplied STROBE pulse
I/F Protocol Using ACK and BUSY signals
Logic Level Compatible with TTL level
These signals represent information for the 1st through 8th bit of
paralleldata, respectively. EachsignalisHIGH when dataislogical1,
and LOW when logical 0.
Fig. 1-6 Timing Charts for Parallel Interface
4-2. Connector Signals
Pin Name Function
1 STROBE Goes low for ≥0.5µs when active.
2 DATA0
3 DATA1
4 DATA2
5 DATA3
6 DATA4
7 DATA5
8 DATA6
9 DATA7
10 ACK 10µs low to acknowledge receipt of data.
11 BUSY Printer sets line low when ready to receive data.
12 PAPER High when paper runs out.
13 SELECT High when printer is on-line.
14 AFXT Printer ignores this signal.
15 Not used.
16 SIGNAL GND Signal ground
17 CHASSIS Chassis ground (isolated from signal ground)
18 +5V +5V DC output from printer
19~30 GND Twisted pair ground return
31 RESET Printer is reset when this signal goes low.
32 ERROR Low when printing cannot continue due to error.
33 EXT GND External ground
34~35 Not used
36 SELECT IN Printer ignores this signal.

– 11 –
Pin Name Function
1 CHASSIS Printer chassis ground
2 TXD Data from printer
3 RXD Data to printer
4 RTS Always space
5 CTS Space when computer is ready to send data. Printer ignores this signal.
6 Not used.
7 GND Signal ground
8-10 Not used.
11 RCH Printer sets line to space when ready to receive data. Same signal as pin 20.
12 Not used.
13 Not used. (single ground)
14-19 Not used.
20 DTR Printer sets line to space when ready to receive data.
21-25 Not used.
5. Serial Interface
When using the serial interface, the optional Serial-Parallel Converter must be connected to the printer.
5-1. General Specifications
Item Specifications
Interface RS-232C level
Synchronization System Asynchronous
Baud rate 300 - 19,200 bits per second (BPS) [selectable]
300, 300, 600, 1200, 2400, 4800, 9600, 19200 BPS
Word length
Start bit: 1 bit
Data bit: 7 or 8 bits (selectable)
Parity bit: Odd, Even or None (selectable)
Stop bit: More than 1 bit length
Signal polarity
Mark: Logic ″1″(–3V to –15V)
Space: Logic ″0″(+3V to +15V)
Handshaking DTR
XON/XOFF
5-2. Connector Signal and Functional Descriptions

– 12 –
6. Serial Interface - SPC-8K (Option)
When using the serial interface, the optional Serial-Parallel Converter must be connected to the printer.
6-1. General Specifications
Item Specifications
Interface RS-232C level
Synchronization System Asynchronous
Baud rate 150 - 19,200 bits per second (BPS) [selectable]
150, 300, 600, 1200, 2400, 4800, 9600, 19200 BPS
Word length
Start bit: 1 bit
Data bit: 7 or 8 bits (selectable)
Parity bit: Odd, Even or None (selectable)
Stop bit: More than 1 bit length
Signal polarity
Mark: Logic ″1″(–3V to –15V)
Space: Logic ″0″(+3V to +15V)
Handshaking DTR
XON/XOFF
ETX/ACK
Data buffer 8KB (standard)
6-2. Connector Signal and Functional Descriptions
Pin No. Signal name Direction Function
1 GND —
2 TXD OUT
3 RXD IN
4 RTS OUT
5 CTS —
6NC
7 GND —
8~10 NC
11 RCH OUT
12~19 NC
20 DTR OUT
21~25 NC
Printer chassis ground.
This pin carries data from the printer.
This pin carries data to the printer.
Always space.
This signal is space when the computer is ready to send data.
The printer does not check this pin.
Unused.
Signal ground.
Unused.
The printer sets this signal to space when it is ready to receive data.
This line carries the same signal as pin 20.
Unused.
The printer sets this signal to space when it is ready to receive data.
Unused.

– 13 –
Handshaking protocols – see table below
6-3. DIP Switch Settings
Switch ON OFF
1 8 data bits 7 data bits
2 No parity Parity checked
3
4
5 Odd parity Even parity
6
7 Data transfer rate – see table below
8
All switches are set to ON before the printer leaves the factory.
Protocol Switch 3 Switch 4
DTR mode ON ON
XON/XOFF mode ON OFF
ETX/ACK mode OFF ON
Baud rate Switch 6 Switch 7 Switch 8
150 OFF OFF OFF
300 OFF OFF ON
600 OFF ON OFF
1200 OFF ON ON
2400 ON OFF OFF
4800 ON OFF ON
9600 ON ON OFF
19200 ON ON ON

– 14 –
7. EE-PROM mode
7-1. Outline
Thesesettings can be changed in the EE-PROM mode by writing data directly to the EE-PROM on the main logic board:
Setting EE-PROM mode
• Send <ESC><SUB>(09)H command.
Canceling EE-PROM mode
• Initialize the printer by sending <ESC>@
7-2. Explanation of special control codes
<ESC>@ Exits printer from EE-PROM mode and initializes the printer.
<ESC>M@ Returns all data in the EE-PROM to the factory settings. After the buffer is cleared, the buzzer sounds. If
the printer is powered off before the buzzer sounds, all data in the buffer is not cleared.
If all data is not cleared from the buffer, operation is not guaranteed. Be sure to allow the buzzer
to sound before you turn the printer off!
<ESC>MWn Code Function Address Capacity
<ESC>MW0 <data> Stores data into entire area of EE-PROM. 00H-7FH 128bytes
<ESC>MW1nm Stores data (m) into the address (n) nH 1 byte
<ESC>MW2<data> Stores auto-start software data into 43H-60H 30bytes
EE-PROM. 61H-7DH 29bytes
• The data (m) used in the commands above are stored in the specified address in order (n).
• When the data to be stored exceeds the specified capacity, subsequent data are ignored.
• Data are stored in the EE-PROM according to the memory map. (See section 3. EDS mode setting and
6-3. EE-PROM Map.)
• After all data are stored, a beep indicates the completion of storage.
• If the printer is powered off during data storage, data stored before power off are valid, but subsequent
operation of the printer is not guaranteed.
Do not power off the printer while data is being stored!
<ESC>MR Dumps all data in the EE-PROM to a hard copy.
For an example of using these control codes, see section 7-4. For the corresponding EE-PROM addresses, see the
EE-PROM memory map in section 3-2. EDS mode setting and 7-3. EE-PROM Map.

– 15 –
Address Function Factory data
00H EDS setting FFH
Bit Function 1 0
b0 Emulation STANDARD/EPSON IBM
Character Table
b1 Standard / EPSON mode Graphics Italics
IBM mode IBM #2 IBM #1
b2 RAM Usage Input Buffer Download Buffer
b3 Paper out Detector Enabled Disabled
Multi-part mode
Function b4 b5
Auto selectable 1 1
Multi-part mode 0 1
Normal mode 1 0
01H EDS setting FFH
Bit Function 1 0
b0 Graphics Direction Bi-directional Uni-directional
b1 Tear-off Disabled Enabled
b2 Line Spacing 1/6″1/8″
b3 Auto LF with CR Disabled Enabled
b4 Zero Style Normal Slashed
b5 Strobe Timing Normal Reverse
02H EDS setting FFH
Print Mode Print Pitch
Function b0 b1 Function b2 b3 b4
LQ 1 1 10cpi 1 1 1
Draft 0 1 12cpi 0 1 1
HS-Draft 1 0 15cpi 1 0 1
17cpi 0 0 1
20cpi 1 1 0
Proportional 0 1 0
Bit Function 1 0
b5 Quiet Disabled Enabled
03H EDS setting FFH
Page Length
Function b0 b1 b2 b3 Function b0 b1 b2 b3
11″/Letter 1 1 1 1 14″/Legal 0101
8″0 1 1 1 10.5″/Executive 1001
11.7″/A4 1 0 1 1 7.25″/Executive 0001
12″0011 3.5″1110
8.5″/Letter 1 1 0 1 5.5″0110
7-3. EE-PROM Map

– 16 –
Bit Function 1 0
b0 Data bits 8bits 7bits
b1 Parity check Disabled Enabled
b2 Parity Odd Even
b3 Protocol DTR XON / XOFF
Bit Function 1 0
b4 Eject direction for cut sheet Front Rear
b5 Skew sensor for cut sheet Disabled Enabled
04H EDS setting FFH
IBM Code Page (Character Table=Graphics, IBM#1, #2)
Function b0 b1 b2 b3 b4 b5
#437 111111
#850 011111
#860 101111
#861 001111
#863 110111
#865 010111
#866 100111
#3840 000111
#3841 111011
#3843 011011
#3844 101011
#3845 001011
#3846 110011
#3847 010011
#3848 100011
#852 000011
#1001 111101
#737 011101
#851 101101
Function b0 b1 b2 b3 b4 b5
#869 001101
#928 110101
#2001 010101
#772 100101
#774 000101
#3001 111001
#3002 011001
#3011 101001
#3012 001001
#3021 110001
#3031 010001
#3041 100001
#3850 000001
#3860 111110
#3861 011110
#3863 101110
#3864 001110
#3865 110110
International Character Set (Character Table=Italics)
Function b0 b1 b2 b3 b4 b5
U.S.A. 111111
France 011111
Germany 101111
England 001111
Denmark-1 110111
Sweden 010111
Italy 100111
Spain-1 000111
Function b0 b1 b2 b3 b4 b5
Japan 111011
Norway 011011
Denmark-2 101011
Spain-2 001011
Latin America 110011
Korea 010011
Ireland 100011
Legal 000011
05H EDS setting FFH
LQ Font Selection
Function b0 b1 b2 b3 b4 b5
Roman 111111
Sanserif 011111
Courier 101111
Function b0 b1 b2 b3 b4 b5
Prestige 001111
OCR B 010111
Orator 000111
06H EDS setting FFH
03H EDS setting FFH