Apple Mouse Cable Repair
.png)
A break in the cord of the Apple Mouse (M0100) stops some or all of its functions: no pointer movement in one direction, no movement at all, or no button. The fault usually comes and goes as the cord is flexed.[1] Each signal has its own wire, so the symptom points to the broken wire.[2] The M0100 was the mouse of the Macintosh 128K, Macintosh 512K, Macintosh 512Ke and Macintosh Plus.[3]
Symptoms
[edit | edit source]| Symptom | Wire to check |
|---|---|
| Pointer stuck at the right of the screen; moves up and down but not left | Brown (Left) |
| Pointer stuck at the left; moves up and down but not right | Orange (Right) |
| Pointer stuck at the top; moves left and right but not down | Green (Down) |
| Pointer stuck at the bottom; moves left and right but not up | Blue (Up) |
| No pointer and no button; other mice work on this computer | Black and red (ground and +5 V) |
- Wiggle the ends of the cord. If the fault comes and goes, the cable is broken. If it does not, try a known-good mouse first: Pina finds a frozen pointer is more often a software problem than a cable.[1]
- A mouse that jams when moved, lifting off the table, has a broken axle bearing; see Apple Mouse Axle Bearing Repair. A button that clicks erratically is the switch; see Apple Mouse Button Switch Replacement.[4]
Safety
[edit | edit source]Switch the computer off before unplugging the mouse. Pina notes that the 128K to Plus seem to tolerate live disconnection but the Macintosh SE and II generally do not.[5]
Tools and parts
[edit | edit source]- Analogue meter on R×1K, or a digital meter on kΩ.[6]
- No. 1 Phillips screwdriver to open the mouse.[7]
- A new DB-9 male plug, soldering iron and wire strippers; or a replacement cord.[1][2] The cords differ between the Alps and Mitsumi versions of the M0100, as do their board connectors.[8]
| DB-9 pin | Wire | Function | J1 (mouse) pin |
|---|---|---|---|
| 1 | Black | Ground | 3 |
| 2 | Red | +5.00 V | 5 |
| 3 | Black | Ground | 3 |
| 4 | Brown | Left | 6 |
| 5 | Orange | Right | 1 |
| 6 | Not connected | Not connected | |
| 7 | Yellow | Switch | 7 |
| 8 | Green | Down | 4 |
| 9 | Blue | Up | 2 |
Apple's own table names the same pins: 1 and 3 ground, 2 +5 V, 4 X2, 5 X1, 7 mouse switch, 8 Y2, 9 Y1, 6 not connected.[9]
Procedure
[edit | edit source]Finding the break
[edit | edit source]- Switch off the computer and unplug the mouse.[5]
.png)
- Open the mouse and unplug the cord from J1 on the circuit board, as in Apple Mouse Button Switch Replacement#Opening the mouse.[7]
- Set an analogue meter to R×1K and zero it, or set a digital meter to kΩ.[6]
- Put one probe on a wire's J1 pin and the other on the matching DB-9 pin from the table above. A good wire reads zero; infinity or over-range is a break.[6]
- Repeat for every wire, flexing the cord near each end while you watch the meter to find which end the break is at.[1][6]
- If every wire tests good, the fault is at the J1 connector. Unplugging and replugging it may scrape tarnish off enough to restore contact; then polish the pins and treat them with a contact stabilant.[6]
Break at the DB-9 end
[edit | edit source]- Cut the cable 2 in from the plug. Pina finds that most breaks lie a short distance from the stress point, and cutting 2 in away makes sure the break goes with it.[1]
- Strip the wires and solder them to a new DB-9 male plug, following the table above and Figure 12-6.[1][6]
Break at the mouse end
[edit | edit source]Pina cuts away 8 in at the mouse end. Breaks there are usually at the first permanent crease in the cord, 5 to 6 in from the mouse body, left by tight tie-wraps in the original packing; the stressed area runs about 2 in either side of the crease.[1] The wires then go back to J1 in the order shown in Figure 12-6. Pina does not describe how to reattach the J1 contacts or the strain relief. The Dead Mac Scrolls gives a new cord as the alternative to repair.[1][2]
Testing
[edit | edit source]- Repeat the continuity test on every wire: each should read zero from end to end.[6]
- With the computer off, plug the mouse in, then switch on. The pointer should move in all four directions and the button should click.[5][2]
Related pages
[edit | edit source]- Apple Mouse
- Apple Mouse Button Switch Replacement
- Apple Mouse Axle Bearing Repair
- Macintosh Plus, Macintosh 128K, Macintosh 512K, Macintosh 512Ke
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Larry Pina, Macintosh Repair & Upgrade Secrets (Hayden Books, 1990), ISBN 0-672-48452-8, chapter 12 "Mouse Repairs", pp. 231-233 (PDF pp. 245-247): intermittent mouse functions, where breaks occur, how much cable to cut away, Figure 12-6, Table 12-2 and the continuity test. Hosted as File:Macintosh Repair & Upgrade Secrets.pdf; see Macintosh Repair & Upgrade Secrets.
- ↑ 2.0 2.1 2.2 2.3 2.4 Larry Pina, The Dead Mac Scrolls (Peachpit Press, 1992), "Early Macs", pp. 85-89. Hosted as File:The Dead Mac Scrolls 1992.pdf; see The Dead Mac Scrolls.
- ↑ Pina, Macintosh Repair & Upgrade Secrets, p. 223 (PDF p. 237).
- ↑ Pina, The Dead Mac Scrolls, pp. 84 and 90-91.
- ↑ 5.0 5.1 5.2 Pina, Macintosh Repair & Upgrade Secrets, p. 224 (PDF p. 238).
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Pina, Macintosh Repair & Upgrade Secrets, p. 233 (PDF p. 247): Table 12-2 and testing the mouse cable for continuity.
- ↑ 7.0 7.1 Pina, Macintosh Repair & Upgrade Secrets, pp. 225-227 (PDF pp. 239-241).
- ↑ Glenn Anderson, "Apple IIc mouse compatibility: some details, schematics, and a chip swap to fix compatibility", TinkerDifferent, 2024-2025, accessed 2026-10-25: "Part numbers on the cords are also different ... as the circuit boards have different connectors."
- ↑ Apple Computer, Guide to the Macintosh Family Hardware, 2nd edition, Addison-Wesley, 1990, chapter 7, Table 7-2, p. 278. Hosted as File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf.