Osborne Vixen Maintenance Guide
Care and routine checks for the Osborne Vixen (Osborne 4). Osborne's preventive-maintenance statements in its Field Service Manual cover the Osborne 1 and the Executive, and say that neither needs scheduled preventive maintenance beyond cleaning the drive heads as conditions require and the case with mild soap and water.[1] No Vixen service manual is hosted here; the Vixen documents are a 1983 engineering drawing package and a 1985 theory of operation manual.[2][3]
Safety
[edit | edit source]The Vixen contains a CRT and a mains power supply. The tube can hold a dangerous charge after the machine is unplugged; read CRT Discharge Procedure before opening the case.
Cleaning
[edit | edit source]- Unplug the machine and remove all diskettes.
- Clean the case with a mild soap and water solution, as Osborne specified for its other machines.[1]
- Inside, remove dust with a soft brush or low-pressure air after discharging the CRT.
Disk drives
[edit | edit source]- Clean the heads with a head cleaning diskette, 97 % isopropyl alcohol or head cleaning fluid, without disturbing the drive's alignment or position, as Osborne specified for the Osborne 1 and Executive.[1]
- The 1983 drive sub-assembly drawing allows either MPI or ALPS half-height drives, with different jumpers:[2]
| Drive | Jumpers |
|---|---|
| MPI, drive A | Pins E and F; second set of pins |
| MPI, drive B | Pins E and F; fourth set of pins |
| ALPS, drive A | First and second sets of pins |
| ALPS, drive B | First and third sets of pins |
The drives take double-sided, double-density, soft-sectored diskettes, formatted in single density (FM) or double density (MFM).[3] See Floppy Drive Repair.
Power supply
[edit | edit source]No Osborne specification for the Vixen supply's output voltages or currents is hosted here, and the Osborne 1 and Executive limits do not apply to it. Sheet 1 of the hosted Vixen schematic set is Osborne's drawing of an Astec switching supply with outputs labelled +12V1, +12V2, +5V and −12V, without component values.[4] Record your machine's readings when it is working, so that you have a baseline for later.
Capacitors
[edit | edit source]The 1983 main logic list has five aluminium electrolytics, C1, C2, C3, C4 and C7, and the I/O list one, C1.[2] The schematic in the same package differs at C2 to C6, and the revision C board renumbers its capacitors. Values are on the Osborne Vixen Capacitor Replacement Guide.
Recommended tools
[edit | edit source]- Cross-head screwdrivers and an IC extractor.
- A means of discharging the CRT; see CRT Discharge Procedure.
- Anti-static strap.
- Digital multimeter.
- Head cleaning diskette or 97 % isopropyl alcohol.
See Recommended Tools for the general workshop kit.
Related pages
[edit | edit source]- Osborne Vixen
- Osborne Vixen Troubleshooting Guide
- Osborne Vixen Capacitor Replacement Guide
- Osborne Vixen Engineering Drawings Mar83
- CRT Discharge Procedure
References
[edit | edit source]- ↑ 1.0 1.1 1.2 Osborne Computer Corporation, Osborne Field Service Manual, Revision 2.0, part no. 2F00040-00, 1983, hosted at Osborne Field Service Manual (Revision 2.0). Sections 7.7.0 and 9.7.0, preventive maintenance.
- ↑ 2.0 2.1 2.2 Osborne Computer Corporation, Vixen Engineering Drawings, March 1983, hosted at Osborne Vixen Engineering Drawings Mar83. Disk drive sub-assembly notes (PDF page 6); lists of materials for the main logic and I/O boards (PDF pages 12 to 15, 27 and 28).
- ↑ 3.0 3.1 Osborne Computer Corporation, Osborne 4 Theory of Operation Manual, Revision 1.0, part no. 2F40006-01, August 1985, hosted as File:Osborne 4 Theory of Operation Manual Rev 1.0 1985.pdf.
- ↑ Osborne Computer Corporation, Vixen schematic set, hosted as File:Vixen Schematic.pdf. Sheet 1, power supply drawing (Astec, drawn 10 August 1983).