2.3 CONTROL CIRCUIT OPERATION
The control circuit consists of three boards: the main board (CO60 MAIN, CO61 MAIN, or CO69 MAIN B), which is the
main control board, the CO60 DRV board, the driver board (used only with the CO60 MAIN board), and the CO60 PNL
board, the control panel board. The CO61 and CO60 MAIN B boards combine main control circuitry and driver circuitry
on one board. This section describes how these boards work.
2.3.1 Control Circuit Operation Overview
The printer’s CPU is an
CPU
that runs at 10 MHz. It controls all the components of the printer. The
gate array contains
various
memory management functions that assign memory
and
areas. The
rationalizes and simplifies the circuitry and contains all the driver circuits for driving the printer mechanism on five chips.
Figure 2-17 shows the control circuits in block diagram form.
CO60 PNL
Control
Panel
CO60 MAIN CO61 MAIN CO60 MAIN B
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parallel
EEPROM
Optional
. . . . .
PROM
512K
MASK
ROM
8 M
PSRAM
i
i
i
Gate array
GAP
Platen-gap adjust lever position sensor
HP
Home-position sensor
RELEASE Release sensor
Front paper-out detector (positioned in front of the printer mechanism)
PE2
Rear paper-out detector (positioned behind the printer mechanism)
Figure 2-17. Control Circuit Block Diagram
2-14
Summary of Contents for LQ-1170
Page 1: ...LQ 1170 24 PIN DOT MATRIX PRINTERS TM LQ8 1170 ...
Page 2: ...L Q 8 7 0 1 1 7 0 SERVICE MANUAL EPSON T Printed on recycled paper ...
Page 101: ...10 9 91 Yes NO Replace pluggable chips on main board 5 6 ...
Page 110: ...Table 5 4 Repair of the Power Supply Board Continued 5 15 ...
Page 118: ......
Page 121: ...REV A Figure 6 2 LQ 870 Lubrication Points 6 3 ...
Page 122: ...REV A Figure 6 3 LQ 1170 Lubrication Points 6 4 ...
Page 134: ...1 I II ...
Page 135: ...REV A Q m u D w IL 0 1 xl Figure A 3 CO60 DRV Board Circuit Diagram A 11 ...
Page 136: ...Figure A 4 CO60 PSB Board Circuit Diagram A 12 ...
Page 138: ...LO SLOE002 OWO9 1Nd 0 9 0 3 5 f l P I 11 I 01 I 6 I 8 1 L 9 I 9 I B I I2 I 2 I 1 ...
Page 142: ...REV A Fl 24ov T3 IsA I I II II AL I CU rl Figure A 10 C060 PSE Board Component Layout A 1 8 ...
Page 143: ...LMS d10 IP IMS dla ...
Page 144: ...REV A A 4 EXPLODED DIAGRAM Figure A l 2 1 Exploded Diagram for LQ 870 A 2 0 ...
Page 145: ......
Page 146: ...REV A Figure A 13 1 Exploded Diagram for Model 5DlO A 22 ...
Page 147: ... 5 2 5 610 c 3 5 9 0 El ...
Page 149: ...REV A A 5 CASE OUTLINE DRAWING Figure A l 4 1 Case Outline Drawing for LQ 870 A 25 ...
Page 151: ...lllllll IllI l l IIIIII II0 IIll III1 I I I C O 6 1 M A I N B o a r d A 3 7 ...
Page 152: ... U nRonenl2 i i C O 6 0 HAIN B t _1 m r OL J IIA IS I 19 CNI 36 I I8 I 23 IS ...
Page 153: ...a i iJ 0 E fig tfti I z ...