Macintosh TV Capacitor Replacement Guide
The Macintosh TV has surface-mount aluminium electrolytic capacitors on its logic board and its TV tuner board. They leak with age, and the electrolyte corrodes pads and traces. Recap-a-Mac describes the logic board as "a simple recapping job" and the tuner as "a bit of a corrosive nightmare" whose non-standard sizes usually need a special order.[1]
Visual inspection and failure signs
[edit | edit source]- Brown or dark residue around the base of a capacitor, or on the board beneath it.
- Green or dull pads and traces near a capacitor.
- Bulged or tilted cans.
- A fishy smell from the electrolyte.
See Capacitor Failure Symptoms for the general picture.
Macintosh TV capacitor lists
[edit | edit source]The values below are from MacDat's capacitor reference, which lists values and counts but no designators, and agree with the counts on Recap-a-Mac's annotated photographs.[2][1]
Logic board
[edit | edit source]| Capacitance | Voltage | Quantity | Type | Location (Recap-a-Mac photograph) |
|---|---|---|---|---|
| 100 µF | 25 V | 1 | SMD aluminium electrolytic | Upper left, beside U26 |
| 10 µF | 16 V | 2 | SMD aluminium electrolytic | Upper left, near U21 and below U26 |
| 47 µF | 16 V | 2 | SMD aluminium electrolytic | Upper right, beside the Cuda chip and battery holder |
TV tuner board
[edit | edit source]
| Capacitance | Voltage | Quantity | Type | Location (Recap-a-Mac photograph) |
|---|---|---|---|---|
| 47 µF | 6.3 V | 1 | SMD aluminium electrolytic | Tuner sub-board |
| 4.7 µF | 35 V | 4 | SMD aluminium electrolytic | Tuner sub-board |
| 4.7 µF | 25 V | 4 | SMD aluminium electrolytic | C12, C13, C14 and C92 on the main tuner board |
| 1 µF | 50 V | 1 | SMD aluminium electrolytic | Tuner sub-board |
| 0.47 µF | 50 V | 2 | SMD aluminium electrolytic | Tuner sub-board |
Analog board
[edit | edit source]Apple's Service Source gives no component values for the Macintosh TV analog board (service part 661-0872) and treats it as a module, and neither MacDat nor Recap-a-Mac lists its capacitors.[3][2] The board is not the LC 520's (661-0192), so an LC 520 list does not apply.[3] Read each value and designator off the board before removing anything. The supply accepts 100–240 V AC,[3] so the primary reservoir sees about 340 V DC on 240 V mains; any replacement there must be rated for that. Discharge the CRT first: the board carries mains voltage and the tube's high voltage.
Capacitor replacement procedure
[edit | edit source]- Discharge the CRT and follow the CRT Discharge Procedure. Do not wear a wriststrap until the CRT is discharged.[3]
- Remove the I/O door (two screws if fitted, then push down the two tabs) and pull the logic board out from the back of the machine.[3]
- To remove the tuner, turn the logic board over, twist the tuner's mounting tab with needle-nose pliers, turn the board back and pull the tuner straight up.[3]
- Photograph both boards and note the polarity of every capacitor.
- Remove each capacitor with hot air or two irons, or by twisting it off gently if the pads are sound. Do not pull a pad off with it.
- Clean off the old electrolyte with isopropyl alcohol and a soft brush. Check every trace and via near each position for continuity.
- Fit the new capacitors, matching polarity to the board markings and the photographs.
- Clean off flux, inspect the joints under magnification, and check for shorts between the supply rails before refitting.
- Refit the tuner and logic board and test both computer and TV functions.
Recommended tools and parts
[edit | edit source]- Temperature-controlled soldering iron with a fine tip, or hot air
- Solder wick and flux
- Isopropyl alcohol (90 % or stronger) and a soft brush
- Multimeter
- Magnifier
- Needle-nose pliers for the tuner tab
- Replacement capacitors of the same value and at least the same voltage rating; surface-mount electrolytics or tantalums sized to the pads. See Recommended Tools.
After a recap
[edit | edit source]Apple gives no rail voltages and no voltage adjustment for this machine; its Adjustments chapter covers geometry, focus, video, convergence, geometric distortion, the yoke and light meter setup.[3] Check that the machine chimes and boots, that TV and audio work, and that the picture is stable. If the picture size or colour is out, use Apple's adjustments (see Macintosh TV General Maintenance#Adjustments).
Related pages
[edit | edit source]- Macintosh TV
- Macintosh TV General Maintenance
- Macintosh TV Troubleshooting
- Macintosh TV Service Source
- Capacitor Failure Symptoms
- CRT Discharge Procedure
References
[edit | edit source]- ↑ 1.0 1.1 Macintosh TV, Recap-a-Mac—link(accessed 2026-09-30) Annotated logic board and tuner board photographs, hosted here as File:Macintosh TV Recap Guide.jpg and File:Macintosh TV Tuner Recap Guide.jpg.
- ↑ 2.0 2.1 Capacitor Reference – Macintosh TV, MacDat—link(accessed 2026-09-30) Secondary source.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Apple Computer, Macintosh TV Service Source, hosted here as File:Macintosh_tv.pdf (see Macintosh TV Service Source). Specifications (Electrical); Take Apart (Analog Board, Logic Board, Tuner Assembly); Adjustments; Exploded View.