Casio PR-420A Service Manual & Parts Catalogue

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(without price)

PR-420A

(ZX-516C)

DR-1212LA

(ZX-516D)

DEC. 1995

INDEX

Table of Contents

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Sunil

February 9, 2025

First 0 comes and trying any function then only E comes in screen

Summary of Contents for Casio PR-420A

Page 1 (without price) PR-420A (ZX-516C) DR-1212LA (ZX-516D) DEC. 1995 INDEX...
Page 2: Table Of Contents
CONTENTS SPECIFICATIONS ......................1 BLOCK DIAGRAM ......................1 CPU (MN158418YCY) PIN FUNCTION ................. 2 DIAGNOSTICS ......................3 TROUBLESHOOTING ....................5 DISASSEMBLY VIEW ....................6 SCHEMATIC DIAGRAMS ..................... 9 PARTS LIST ........................ 12...
Page 3: Specifications
1. SPECIFICATIONS Roll paper size : Width: 57 ~ 58 mm Ink ribbon : Red/Black: RB-02 Green/Black: GB-02 Power source : AC 100, 120, 220 or 240 (±10 V), 50/60 Hz • Refer to the operation manual for other specifications. 2.
Page 4: Cpu (Mn158418Ycy) Pin Function
3. CPU (MN158418YCY) PIN FUNCTION Pin No. Signal I / O Function 1~7, 64 P00~P13 Common signal for keyboard 8~12 P20~P22, P32, P33 Key signal from keyboard Timing pulse signal from printer DEBIN Reset pulse (Not used) IRQCNT Auxiliary timing (VDD) Motor control signal Ribbon shift signal for printer 18~30...
Page 5: Diagnostics
4. DIAGNOSTICS OPERATION DISPLAY PRINT OUT ÷ + – -888.888888888 -888.88888888 CUT 6 CUT 6 • 0.1234567 CUT 6 0.123456 CUT 4 0.1234 M– UP 3 0.124 ÷ 5/4 2 0.12 5/4 1 5/4 0 5/4 ADD 0.123 × 5/4 ADD 0.123 ×...
Page 6 OPERATION DISPLAY PRINT OUT • • 0 • • · – – PRINT 5/4 ADD -0.02 1 • ÷ 1 • ÷ ÷ PRINT 5/4 ADD -0.02 0 • 0 1 ÷ ITEM 5/4 ADD 1 • = -0.02 0 • 0 1 –...
Page 7 3. OPERATION CHECK OPERATION DISPLAY NOTE MAIN MENU COMP BASE GRAPH EQUA PRGM LINK CONT RESET RESET RESET RESET ALL MEMORIES? RESET ALL RESET ALL MEMORIES! SHIFT AC No Display Lx375 TEST Press the above keys at the same time. 1.
Page 8: Troubleshooting
5. TROUBLESHOOTING Trouble Cause Checkpoint Note 1) Does not work • Defective power transformer Secondary voltage VDD, VSS, VM, VF1, and at all. of transformer VF2 are OK? • Defective LSI Waveforms of each 2) No display. • No voltage at VF1, VF2 VF1, VF2 •...
Page 9: Disassembly View
6. DISASSEMBLY VIEW 20 × 2 18 × 4 12 × 3 13 × 3 — 6 —...
Page 10 Connection Voltage Power Cord Transformer Projection side Yellow 100V Black Black Projection side Blue 120V Marking side Black Brown Black 220V Blue White 240V Brown Black Blue INPUT OUTPUT 24 × 2 — 7 —...
Page 11 — 8 —...
Page 12: Schematic Diagrams
7. SCHEMATIC DIAGRAM 7-1. Main PCB (ZX-516) — 9 —...
Page 13 7-2. Key Matrix — 10 —...
Page 14 7-3. Printer Pin Arrangement Diagram Connection Pin No. Pin No. Connection RD terminal Character selective magnet column No.1 (Not used) Character selective magnet column No.1 Notes: 1. Column numbers match the physical arrange- ment of the columns on the print wheels. 2.
Page 15: Parts List
8. PARTS LIST — 12 —...
Page 16 — 13 —...
Page 17 8-11-10, Nishi-Shinjuku Shinjuku-ku, Tokyo 160, Japan Telephone: 03-3347-4926...

This manual is also suitable for:

Dr-1212la Zx-516c Zx-516d