– 69 –
*9
+40V Line
+40V
±
5%
Between Pin 5 and Pin 3 of CN1
+5V Line
+5V
±
5%
Between Pin 1 and Pin 2 of CN1
DC Power abnormal.
Check RESET circuit;
replace parts.
Check crystal circuit;
replace parts.
1) Replace CPU or ROM.
2) Check relevant circuit.
NO
NO
NO
NO
See 4-2. Power Supply
Circuit Abnormal.
4.
Repair by Parts Replacement
4-1. Does not Operate at All with Power on
*10 See (2) waveform in item 5 of Chapter 6.
*11 See (1) waveform in item 5 of Chapter 6.
START
+40V, +5V
are
supplied? *9
YES
RESET
signal becomes
HIGH? *10
YES
Crystal
waveform is
normal? *11
YES
ROM OE
signals become
LOW?
YES
Carriage motor abnormal.
Check operation.
END
Summary of Contents for LC-8521
Page 1: ...DOT MATRIX PRINTER LC 8521 TECHNICAL MANUAL THIRD EDITION ...
Page 4: ......
Page 6: ... 2 ...
Page 24: ... 20 ...
Page 26: ... 22 ...
Page 38: ......
Page 42: ... 38 ...
Page 44: ......
Page 54: ......
Page 56: ... 52 ...
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 ...