Power Macintosh G3 All-in-One Capacitor Replacement Guide
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Capacitor notes for the Power Macintosh G3 All-in-One. The logic board is the beige G3 board, whose list is on Power Macintosh G3 (Beige) Capacitor Replacement Guide. The display side has three boards of its own: the analog board and the CRT video (neck) board, which 68kMLA members describe as an LG monitor design, and the power supply board.[1] Apple's Service Source gives no capacitor data. No designators have been published for these boards, so the lists below are values only, from one owner's recap.
Safety
[edit | edit source]The analog board and power supply carry mains and CRT high voltage. Discharge the CRT before removing the power supply or the analog board, as Apple's procedures require, following CRT Discharge Procedure, and remove the anode cap before lifting out the analog board.[2] Work on the boards out of the machine.
Analog board
[edit | edit source]| Value | Voltage | Quantity |
|---|---|---|
| 1000 µF | 16 V | 1 |
| 470 µF | 16 V | 1 |
| 330 µF | 25 V | 1 |
| 100 µF | 250 V | 1 |
| 100 µF | 100 V | 2 |
| 100 µF | 50 V | 1 |
| 100 µF | 25 V | 2 |
| 100 µF | 16 V | 1 |
| 47 µF | 200 V | 1 |
| 47 µF | 160 V | 1 |
| 47 µF | 100 V | 1 |
| 47 µF | 16 V | 2 |
| 22 µF | 16 V | 1 |
| 10 µF | 160 V | 1 |
| 10 µF | 50 V | 3 |
| 10 µF | 25 V | 1 |
| 10 µF | 16 V | 1 |
| 4.7 µF | 250 V | 1 |
| 3.3 µF | 100 V | 1 |
| 3.3 µF | 50 V | 1 |
| 2.2 µF | 160 V | 1 |
| 1 µF | 160 V | 1 |
That is 27 capacitors.[3]
CRT video (neck) board
[edit | edit source]| Value | Voltage | Quantity |
|---|---|---|
| 47 µF | 100 V | 1 |
| 22 µF | 160 V | 1 |
| 22 µF | 50 V | 1 |
| 47 µF | 16 V | 2 |
| 10 µF | 100 V | 3 |
| 0.1 µF | 50 V | 3 |
Power supply board
[edit | edit source]No capacitor list for the power supply board is publicly readable. One owner's list for the power supply, analog board and deflection board is attached to a 68kMLA thread as a PDF.[1] Read the values off the board, and photograph it before removing anything.
Owners' reports point at the supply in these cases: main rails that rise partway and collapse with a buzz while the 5 V standby rail stays steady, and a supply that clicks while the machine chirps and restarts.[4][1] Reflow the 20-pin connector on the supply board while it is out; its joints tend to crack.[5]
Flyback and other parts
[edit | edit source]Owners often replace the flyback and the capacitors together.[5] The LG flyback is 6174Z-1009A on one owner's list and 6174Z-1009D on another machine; a 6174Z-1003D did not work as a substitute for one owner.[3][6] One owner who replaced the flyback also replaced the C5404 output transistor, which he describes as known to fail.[1] See Power Macintosh G3 All-in-One Troubleshooting#Display and power supply faults (owners' reports).
Procedure
[edit | edit source]- Remove the chassis carrier, housing and CRT EMI shield, discharge the CRT, and take out the power supply board and the analog/video board as described on Power Macintosh G3 All-in-One General Maintenance.[2]
- Replace capacitors one at a time, matching value, voltage and polarity. Check every new part's orientation before refitting: one owner found a capacitor he had fitted the wrong way round when he went back over his recap.[5]
- Refit the power supply board with TH901, P908, P913, P906 and P905 connected before it is lowered into place.[2]
- After replacing the analog/video board, run Apple's cutoff and white balance adjustments.[2]
Related pages
[edit | edit source]- Power Macintosh G3 (Beige) Capacitor Replacement Guide
- Capacitor Failure Symptoms
- CRT Discharge Procedure
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 68kMLA forum thread "Power Macintosh G3 All In One (Molar Mac) Power Supply, Analog Board, And Deflection Board Recap List", November 2023 to November 2024. jajan547: the beige G3 and AIO share the logic board; the power supply, CRT, analog board and deflection board come from an LG monitor; he recapped four machines that chirped and restarted with the supply clicking; his recap list for the power supply, analog board and deflection board is a PDF attachment on the forum, corrected in May 2024 for three wrong values; the analog board carries an LG part number and no Apple number. Durosity: recapped most of the power and analogue boards and replaced the flyback and C5404 transistor; his fault remained. Community repair report.
- ↑ 2.0 2.1 2.2 2.3 Apple Computer, Power Macintosh G3 All-In-One Service Source, hosted here as File:Power Macintosh G3 All-In-One Service Source.pdf (see Power Macintosh G3 All-In-One Service Source). PDF page numbers: CRT EMI shield pp. 70-72 (high voltage warning); Power Supply pp. 73-78 (cables P904, P905, P906, P908, P911, P912, P913 and TH901; refitting order); Analog/Video Board pp. 79-83 (discharge the CRT and disconnect the anode cap first; P502, P503, P505, P506, P507, P508, P701, P702, P703); Adjustments pp. 148-172 (cutoff after replacing the CRT or analog/video board); Exploded View p. 185 (analog/video board 661-2041, power supply board 661-2042).
- ↑ 3.0 3.1 3.2 3.3 68kMLA forum thread "G3 AIO analog board/psu cap list", July 2022 to February 2023. bsteckler, 31 August 2022: cap list for the G3 AIO analog board (27 values) and CRT neck board (11 values), no designators; flyback 6174Z-1009A (LG part); he recapped preventively and did not do the power supply. Community repair report.
- ↑ 68kMLA forum thread "PowerMac G3 AIO PSU Recapping Help", August-September 2026. cgober: standby 5 V steady at about 4.9 V; the main 5 V, 3.3 V and 12 V rails rise partway then collapse with a fan twitch and a buzz; the machine chimed when run from an ATX supply; the supply looked fine visually. Community repair report.
- ↑ 5.0 5.1 5.2 68kMLA forum thread "G3 AIO 'Molar' issues - Flyback? Caps?", August-September 2024. Torbar: reflow the roughly 20-pin connector on the power supply board that feeds the motherboard, because its joints tend to crack. Daniël: if replacing the flyback, do the capacitors as well. Durosity: found one capacitor fitted wrongly and one out of spec after his first recap, and refitted them all; replacing every capacitor, the flyback and the CRT did not cure his machine. Community repair report.
- ↑ 68kMLA forum thread "Molar Mac - Dead Display", September 2026. sciencegirl100: flyback 6174Z-1009D; someone tried a 6174Z-1003D without success; reflowing the flyback's joints revived the CRT. Community repair report.