– 66 –
*6 Power Supply Unit
+40V Line
+40V
±
5%
Between Pin 5 and Pin 3 of CN1
+5V Line
+5V
±
5%
Between Pin 1 and Pin 2 of CN1
1) Replace I/F cable.
2) Replace main logic board.
3) Check host computer.
1) Replace main logic board.
2) Replace printer mecha-
nism.
3) Replace control panel
board.
Replace printer mechanism.
Replace power supply unit.
C
D
NO
A
B
3
NO
NO
NO
YES
Printing begins?
YES
Printing
operation normal?
YES
Stop print program.
END
Carriage moves
with hand?
YES
Output
(+40V, +5V)
of power supply unit is
normal? *6
NO
Turn power off.
Fuse blows out?
YES
Replace fuse.
Remove connector CN3 from
main logic board.
Turn power on.
4
Summary of Contents for LC-8521
Page 1: ...DOT MATRIX PRINTER LC 8521 TECHNICAL MANUAL THIRD EDITION ...
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Page 6: ... 2 ...
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Page 64: ... 60 ...
Page 80: ... 76 ...
Page 101: ... 97 Blank Page ...
Page 102: ... 98 4 Wiring Scheme of Printer ...
Page 103: ... 99 ...
Page 104: ... 100 5 Electrical Parts 5 1 Main Logic Board 5 1 1 Circuit Diagram ...
Page 105: ... 101 ...
Page 106: ... 102 ...
Page 107: ... 103 Blank Page ...
Page 108: ... 104 5 1 2 Component Layout ...
Page 109: ... 105 ...
Page 116: ... 112 5 4 Power Supply Unit 5 4 1 Circuit Diagram ...
Page 117: ... 113 5 4 2 Component Layout ...
Page 120: ... 116 6 Serial Parallel Converter Board Option 6 1 Wiring Scheme ...