User manual EPSON LX300+

[. . . ] EPSON TERM NAL PR NTER LX-300 SERVICE MANUAL ( ) EPSON PRECAUTIONS Precautionary notations throughout the text are categorized relative to 1) personal injury and 2) damage to equipment. DANGER Signals a precaution which, if ignored, could result in serious or fatal personal injury. Great caution should be exercised in performing procedures preceded by DANGER Headings. WARNING Signals a precaution which, if ignored, could result in damage to equipment. The precautiomry measures itemized below should always be observed when performin grepair/ maintenance procedures. DANGER 1. ALWAYS DISCONNECT THE PRODUCT FROM BOTH THE POWER SOURCE AND PERIPHERAL DEVICES PERFORMING ANY MAINTENANCE OR REPAIR PROCEDURE. BASIC SAFETY MEASURES AS DICTATED FOR ALL ELECTRONICS TECHNICIANS IN THEIR LINE OF WORK. 3. NO WORK SHOULD BE PERFORMED ON THE UNIT BY PERSONS UNFAMILIAR WITH CONNECT THE UNIT TO A POWER SOURCE UNTIL INSTRUCTED TO DO SO. [. . . ] Paper End Sensor Circuit Diagram 2. 3. 5 Release Lever Position Sensor Circuit This printer has a comector switch to detect the type of paper handling. The system IC receives a HIGH or LOW signal from the comector switch to indicate whether the paper is fed using friction feed or push tractor feed. Thecomector switch is closed (LOW) when friction feed is selected and is open ~HIGH) when push tractor feed is selected. +5V SYSTEM IC (lCl) R53 Release Sensor A NO 58 R54 J-' Figure 2-16. Release Lever Position Sensor Circuit Diagram 2-14 Flev. A LX-300 Sarvica Manual 2. 3. 6 Carriage Motor Driver Circuit Operating Pdnoipk Figure 2-17 shows the carriage motor driver arcuit. The carriage motor driver uses an open-loop, constant-current drive arrangement. The motor is driven with 2-2 phase excitation and 1-2 phase excitation. IC (Al) detects the amount of current in the carriage motor coils and regulates the current. The amount of current flowing in the coils varies, depending on the speed of the carriage motor. The motor driver IC sets the coil current to correspond to the carriage motor speed. Ports PAO - PA3 on the CPU block control the stepping motor via the gate array block in IC1. The ~rriage motor driver Table 2-9. Carriage Motor Drive Modes t 1 Driver Mode 3 x speed Excitation Type 2-2 phase 1-2 phase I Drive Frequency Type 1080 pps 1800 pps Standard Print Character I I 80dpiprinting 80 dpi printing 180 dpi printing (LQ) 120, 90 d~i mintirm 180, 120, 90 dpi printing T I Home position seek (draft) I I I 2 x speed 1 x speed I 1-2 phase 1-2 phase 1-2 phase 800 pps 533pps 830 ppa 2/3 x speed I 7/8 x speed I I +5V+5V tt R4{ {R5 CR MOTOR DRIVE IC(A1) MOTOR ASSY. , CR SYSTEM IC(IC1) 1 BF1 OUT ~ BF20UT `% BF1 IN = BF21N `a PA3 * +5V 1- TDB ` 4 INB 1 OA 1 o-P OB 10 o-e CR-B VP+ = CRA CR-A CRB PA2 ~ PA1 `la PAO 141 CRII = CR12 2 R8 `1 b , sA~sB PGA GB - A ` 1 1t Figure 2-17. Carriage Motor Driver Circuit Diagram Rev. A 2-15 Operating Principles LX-3(M Service Manual 2. 3. 7 Paper Feed Motor Driver Circuit Figure 2-18 shows the paper feed motor driver circuit, an open-100P, constant-voltage drive with 1-2 phase excitation. The ports (pins 137- 140) on the system IC (ICI) are used to control the stepping motor. The pulse signal from the IC1 controls four transistors and the stepping motor. l%e motor is driven at five speeds, 800, 900, 1000, 1200, and 1300 pps, to correspond to the idling voltage and the paper handling condition. At the holding time, The pFCOM voltage is chang4-VP into VL via A4 by the IC1. " SYSTEM IC (ICI) ( R84 PFA - ' 3 7 13s PFA PB- `3 R87 PFB nm7 ( {" `: MOTOR ASSY. , PI Q11 Q1 Q13 Q14 PF~ PFA Pm Pm R86 Ra5 `"O I ( <<-: * `L `1 VP Figure 2-18. Paper Feed Motor Driver Circuit Diagram 2. 3. 8 Printhead Driver Circuit Figure 2-19 shows the printhead driver arcuit block diagram. Print data, already expanded into image data, is split by the CPU block and transferred to the latch arcuit in the gate array block in the system IC (ICI). Port AN6 (pin 66) of ICI samples the voltage of the +35 VDC line via the A/D converter. By sampling the +35 VDC line voltage and dete rmining the length of the head drive signal, it is possible to maintain the energy supplied to the head at a constant level. If the voltage from the +35V line is HIGH, ICI shortens the output pulse. If the voltage from the +35 VDC line is LOW, ICI lengthens the output pulse. SYSTEM IC (ICI) I HD1 HD2 HD3 HD4 HDs HD6 HD7 HDs HD9 ;p~~ At& 68 Printhead 1 `~ RIO F14 D1 -c? Rll ~ Figure 2-19. [. . . ] I printer Mechanism I- I I MOTOR ASSY. , PF Release Lever Position Sensor I El' BOARD ASSY. , PSB I PSE EJ EEcl -P CN1 HOST COMPUTER BOARD ASSY. , MAIN m I CN1O CN11 CS BOARD , --------------------[Color Upgrade Kit ~ I I I , . Cable Connections Rev. A A-1 LX-300 Service Manual Appendix Table A-1. Connector Summary Board Connector CN1 CN2 CN3 CN4 CN5 CN6 CN7 CN8 CN9 CN1O CN11 Function Parallel, serial interface CR motor assembly PF motor assembly PSWPSE board assembly Printhead PE sensor HP sensor Release lever position sensor CS motor assembly (optional) Color ribbon sensor (optional) CS motor assembly (optional) Color ribbon sensor (optional) CS motor assembly (optional) Color ribbon sensor (optional) Pins -- 6 6 5 12 2 2 2 , . L 1 2 3 4 5 6 I/o 0 0 0 0 Signal Name CR A CR B CRCOM CRCOM CR-A I CR-B Function CR motor assembly Phase A CR motor assembly Phase B CR motor assembly Common CR motor assembly Common CR motor assembly Phase ­A I CR motor assembly Phase ­B Table A-3. [. . . ]