Canon V-20 Service Manual
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The Canon V-20 Service Manual is Canon's English service manual for the European versions of the Canon V-20 MSX computer. It covers the UK version and the French version and notes every difference between them; it does not cover the Japanese V-20.[1][2] The scan has 79 pages. No part number or date is printed on the pages read.
Contents
[edit | edit source]| Section | Subjects | PDF pages |
|---|---|---|
| I. Introduction | Version differences, specifications, interfaces, parts (photos I-1 to I-3) | 4 to 7 |
| II. Maintenance | Cautions, disassembly, reassembly checkpoints, adjustment of +5 V and the VDP clock, troubleshooting flow charts | 8 to 18 |
| III. Circuitry description | Block diagram, CPU, memory, I/O ports, PPI and keyboard, PSG and joysticks, VDP, cassette, printer, power supply, test program | 19 to 52 |
| IV. Connector pin description | Pin assignments of every external connector, including the cartridge bus | 53 to 57 |
| V. Assembly diagrams and parts list | Exploded view, main parts, keyboard parts, main PCB and power PCB assembly diagrams and parts lists | 58 to 69 |
| VI. Circuit diagram | Main PCB and power supply circuit diagrams, waveforms | 70 to 73 |
| VII. Keyboard | Keyboard matrix and key input modes for both versions | 74 to 77 |
| VIII. Appendix | PAL encoder (UK) and RGB encoder (French) circuit and assembly diagrams | 78 to 79 |
Pages most used for repair:
- Section II-4 (PDF page 11): set +5 V to 5 ± 0.25 V with VR1 on the power PCB, measured at pins 1 and 4 of connector J7; set the VDP clock with trimmer TC1, measured at pin 37 of the VDP (U30).
- Section II-5 (PDF pages 12 to 18): troubleshooting flow charts, starting with the power checks on PDF page 13.
- Section III-10 (PDF page 46): how the power supply works.
- Section III-11 (PDF page 47): the diagnostic test cartridge.
- Sections V-5 and V-7 (PDF pages 64 and 69): main PCB and power PCB parts lists, with every capacitor's value and voltage.
- Fig. VI-2 (PDF page 70): the power supply circuit diagram.
What this manual does not contain
[edit | edit source]It does not cover the Japanese V-20, which has a TMS9918ANL video chip and a Japanese keyboard.[4] It has no parts list for the encoder boards; their values appear only on the appendix diagrams, without voltage ratings. The test program is described but the PROM contents are not included.
Pages that cite this document
[edit | edit source]- Canon V-20: specifications and hardware.
- Canon V-20 General Maintenance: cautions, disassembly, reassembly and adjustment.
- Canon V-20 Troubleshooting Guide: the troubleshooting flow charts, power supply and test program.
- Canon V-20 Capacitor Replacement Guide: the power PCB and main PCB parts lists.
References
[edit | edit source]- ↑ Canon V-20 Service Manual (GB), Internet Archive, 26 October 2018—link(accessed 2026-10-21) 79-page PDF uploaded by [email protected], dated 1984-09 in the item's metadata; the first page reads "Scanned by abuur, converted to pdf by HansO, 2009".
- ↑ Canon, V-20 Service Manual, section I "Introduction" (PDF page 4): the V-20 comes in a UK version and a French version, with a table of the parts that differ (top and bottom panels, mains lead, ROM, RF modulator fitted to the UK version only). Hosted as File:Canon V-20 Service Manual.pdf.
- ↑ Canon, V-20 Service Manual, index (PDF pages 2 and 3) and the section headings in the body. See File:Canon V-20 Service Manual.pdf.
- ↑ Canon V-20, MSX Resource Center wiki, 6 May 2026—link(accessed 2026-10-21) The Japanese V-20 of 1984: TMS9918ANL video, YM2149 PSG, JIS keyboard, NEC D780C-1 CPU.
Download: Canon V-20 Service Manual.pdf