Acorn A400-1 and R140 Service Manual
The 400/1 & R140 Service Manual is Acorn Computers' dealer service manual for the Archimedes 400/1 series (A410/1, A420/1 and A440/1) and the R140 RISC iX workstation derived from it. It is part number 0483,075, Issue 1, first published in July 1989 by Acorn Computers Technical Publications Department. The hosted scan has 112 pages; the text has a searchable layer and the drawings at the end are images.
Acorn structured it for module-level fault finding, with a separate chapter of component-level fault finding for the main PCB "where full service facilities and test equipment are available" (About this manual, p. 5).
Contents
[edit | edit source]Acorn's contents list, with printed page numbers:
- About this manual, p. 5
- Technical specification, p. 7: computer main unit, connectors, dimensions, optional equipment, environmental, electrical safety, operating system, screen modes, packaging and installation
- System description, p. 13: introduction, general, the I/O system, the sound system, hard disc drives and interface
- Disassembly and assembly, p. 17: top cover, main PCB, floppy disc drive, power supply unit, front moulding, fan, main unit assembly, keyboard, mouse
- Fault-finding information, p. 21: checking a "dead" computer 22, functional testing 24, main PCB functional test 26, hard disc drive tests 27, other tests 31, keyboard test 34, expansion tests 36, backplane tests 41
- Main PCB fault diagnosis and repair, p. 43: tools, repairing a "dead" computer, test ROMs 44, repairs following functional testing 47, keyboard and mouse, expansion cards
- Appendices, p. 49: parts list 51; upgrading 65 (expansion card, WE32206 floating point co-processor and second floppy drive installation instructions); main PCB links and test points 67; main PCB plugs and sockets 67; Technical Service Bulletins 69 (including 2/89, 400/1 RAM upgrade fitting)
- Drawings, p. 71: main PCB plugs and sockets, links and test points, function map, final assembly (410/1, and 420/1 and 440/1), lower case assembly (410/1, and 420/1 and 440/1), and the two-sheet main PCB circuit diagram. All of these are in the scan (PDF pp. 95-112).
What it settles
[edit | edit source]- Backup batteries (p. 7): "Two LR06 (AA size) 1.5 V Manganese Alkaline cells fitted inside computer main unit. Batteries require replacement once a year." They connect to the main PCB at PL10 (p. 17), and the parts list carries the battery holder assembly as part 0176,009.
- Clock and CMOS RAM test (p. 47): with the power off, IC29 pin 8 should read about 2.8 V. If it does not, inspect PL10, D16 and the cells, which should each read more than 1.4 V. If IC29 consistently fails on the same data bits, change it.
- Power supply: a 55 W 240 V unit, part 0183,002, in the final assembly lists (p. 58). It has a double-pole switch with both live and neutral fused, and Acorn treats it as a service replacement item (p. 18).
- Main unit dimensions (p. 9): 97 mm high excluding feet, 362 mm wide, 406 mm deep. The keyboard is 46 × 485 × 205 mm.
What this manual does not contain
[edit | edit source]- No component-level data for the power supply, which is replaced as a unit.
- Nothing on the original 1987 A410 and A440 board (see the Archimedes 440 Service Manual) or on the A540 (see the Acorn Archimedes 500 Series and R200 Series Service Manual).
Pages that cite this document
[edit | edit source]- Acorn Archimedes A410
- Acorn Archimedes A420
- Acorn Archimedes A440
- Acorn Archimedes 400/1 Series Maintenance Guide
- Acorn Archimedes 400/1 Series Troubleshooting Guide
- Acorn Archimedes 400/1 Series Capacitor Guide
- Acorn R140
- Acorn R140 Documentation, the R140 Operations Guide
Download: Acorn A400-1 and R140 Service Manual.pdf