iMac G3
 | |
| The original Bondi Blue iMac (David Fuchs and Rama, Wikimedia Commons, CC BY-SA 4.0) | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | All-in-one personal computer |
| Released | 15 August 1998 |
| CPU | PowerPC G3 at 233 MHz to 700 MHz |
| Memory | 32 MB to 256 MB standard; SO-DIMMs (tray-loading) or PC100 DIMMs (slot-loading) |
| Storage | 4 GB to 60 GB ATA hard disk |
| Display | Built-in 15-inch CRT, 13.8-inch viewable |
| Sound | — |
| Graphics | ATI Rage IIc, Rage Pro, Rage Pro Turbo, Rage 128 Pro and Rage 128 Ultra |
| Media | Tray-loading CD-ROM (1998-1999); slot-loading CD-ROM, DVD-ROM or CD-RW (1999-2001) |
| Ports / interface | Two USB; 10/100BASE-T Ethernet; modem; audio; FireWire and VGA out on later models |
| OS / Firmware | Mac OS 8.1 (first model) to Mac OS 9 and Mac OS X |
The iMac G3 is Apple's first iMac: an all-in-one Macintosh with a 15-inch CRT, a PowerPC G3 processor and USB in place of Apple's older ports, introduced in August 1998 in a translucent coloured case. There are two physical designs. The tray-loading iMac of 1998-1999 (233, 266 and 333 MHz) has its logic board on a chassis that slides out of the bottom and RAM on the processor card. The slot-loading iMac of October 1999 onwards (350 to 700 MHz) is a revised case with a slot-loading optical drive and memory behind a door under the machine.[1][2]
The iMac G3 has a CRT and an internal power supply on the same board as the CRT drive circuits. Read CRT Discharge Procedure before opening one: Apple's Service Sources call for the CRT to be discharged before work on the analogue and power boards.[1][2]
Models
[edit | edit source]| Model | Introduced | Processor | RAM (standard / maximum) | Graphics | Notes |
|---|---|---|---|---|---|
| iMac, Bondi Blue (M6709LL/A) | 15 August 1998[3] | 233 MHz | 32 MB / 128 MB | ATI Rage IIc, 2 MB SGRAM | IrDA port; reset button on the side; Mac OS 8.1[1] |
| iMac, Bondi Blue (M6709LL/B) | 26 October 1998[4] | 233 MHz | 32 MB / 256 MB | ATI Rage Pro, 6 MB SGRAM | No IrDA; reset with the front power button; Mac OS 8.5[1] |
| iMac (266 MHz), five colours | 5 January 1999[5] | 266 MHz | 32 MB / 256 MB | ATI Rage Pro Turbo, 6 MB SGRAM | Blueberry, Strawberry, Grape, Tangerine, Lime; 6 GB disk[1] |
| iMac (333 MHz) | 15 April 1999[6] | 333 MHz | 32 MB / 256 MB | ATI Rage Pro Turbo | Same five colours; only the processor changed[1] |
| iMac (Slot Loading), iMac DV, DV Special Edition | 4 October 1999[7] | 350 or 400 MHz | 64 MB / 512 MB | not given | FireWire and VGA out on the DV and Special Edition |
| iMac (Summer 2000), including DV+ | 19 July 2000[8] | 350 to 500 MHz | 64 MB / 1 GB | not given | FireWire and VGA on all models[8] |
| iMac (Early 2001) | 22 February 2001[4] | 400, 500 or 600 MHz | 64 or 128 MB / 1 GB | ATI Rage 128 Pro (8 MB) or Rage 128 Ultra (16 MB)[9] | Flower Power and Blue Dalmatian patterns[4] |
| iMac (Summer 2001) | 18 July 2001[4] | 500, 600 or 700 MHz | 128 or 256 MB / 1 GB | ATI Rage 128 Ultra, 16 MB[10] | Indigo, Snow and Graphite; CD-RW in all models |
Apple gives the slot-loading iMac as introduced on 4 October 1999; Wikipedia gives 5 October.[7][4]
Hardware
[edit | edit source]Tray-loading models
[edit | edit source]The logic board, hard disk and CD-ROM drive sit on a logic board/mass storage chassis that slides out of the bottom after the lower access cover is removed. The processor and boot ROM are on a plug-in processor card, which also carries the two SO-DIMM sockets for 144-pin SDRAM. The power supply board, analogue/video board and CRT are in the upper housing; power runs from the power supply board through a power filter board to the logic board.[1] Apple introduced "Version 2" analogue/video and power supply boards, CRTs and cables that are not interchangeable with the originals, so exchange like for like.[1]
Slot-loading models
[edit | edit source]A single power/analog/video board drives the CRT and supplies trickle power. The down converter board, attached to the logic board, produces the +12 V, +5 V and +3.3 V rails, and the logic board and down converter board come out of the machine together. A PMU microcontroller handles power, sleep, PRAM and the clock, powered from the logic board battery when the machine is unplugged.[2] Memory is two PC100 DIMMs behind a door in the bottom of the case; there is no soldered system RAM, so the machine will not run with both slots empty.[2][11]
Clock battery
[edit | edit source]Apple's specification pages give a 3.6 V lithium cell.[3][7] On the slot-loading models a good battery reads 3.3 to 3.7 V; below 3.2 V, replace it and reset the PMU.[2]
Common problems
[edit | edit source]- No power, a CRT that does not light, or a machine that switches off after the chime: work through Apple's power tests on iMac G3 Troubleshooting.
- Error beeps instead of a chime: memory, including EDO modules fitted by mistake, or the boot ROM.[1]
- A PMU that crashes and drains the battery in days on slot-loading models.[2]
- The inner bezel of slot-loading models is brittle and can break into pieces when the case is opened; MacEffects makes a replacement.[12]
Maintenance and repair
[edit | edit source]- iMac G3 General Maintenance
- iMac G3 Troubleshooting
- iMac G3 Capacitor Replacement Guide: Console5's lists for the tray-loading boards
- CRT Discharge Procedure
Documentation
[edit | edit source]- iMac G3 Service Source (tray-loading): Apple's manual for the 1998-1999 models.
- iMac G3 Service Source (Summer 2001): Apple's manual for the last slot-loading models.
- Apple Memory Guide: memory rules for each model.
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Apple Computer, iMac Service Source (tray-loading models), hosted here as File:iMac G3 tray-loading Service Source.pdf (see iMac G3 Service Source (tray-loading)). PDF page numbers: Standard Configurations pp. 19-20; Model Comparison pp. 21-25; Memory pp. 62-66; Testing for Power pp. 86-91; Power-On Self Test p. 94; Take Apart pp. 126-256; Adjustments pp. 270-295.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Apple Computer, iMac (Summer 2001) Service Source, hosted here as File:iMac G3 Summer 2001 Service Source.pdf (see iMac G3 Service Source (Summer 2001)). PDF page numbers: What's New pp. 3-6; SDRAM DIMM pp. 17-19; Logic Board p. 44; Power/Analog/Video Board pp. 81-98; Testing for Power pp. 135-139; PMU pp. 140-141; Logic Board Battery p. 143.
- ↑ 3.0 3.1 Apple, "iMac - Technical Specifications" (retrieved 2026-10-02). Introduced 8/15/1998; G3 at 233 MHz; 512K backside cache; two SO-DIMM slots, 32-128 MB; 80 W; 3.6 V lithium battery; 15.8 × 15.2 × 17.6 in, 40 lb.
- ↑ 4.0 4.1 4.2 4.3 4.4 Wikipedia, "iMac G3" (retrieved 2026-10-02). Release dates of the revised Bondi Blue, slot-loading, Summer 2000, Early 2001 and Summer 2001 models; DV and DV+ models; Flower Power and Blue Dalmatian patterns. Used for dates and history only.
- ↑ Apple, "iMac (266 MHz) - Technical Specifications" (retrieved 2026-10-02). Introduced 1/5/1999, discontinued 4/15/1999; five colours.
- ↑ Apple, "iMac (333 MHz) - Technical Specifications" (retrieved 2026-10-02). Introduced 4/15/1999, discontinued 10/7/1999.
- ↑ 7.0 7.1 7.2 Apple, "iMac (Slot Loading) - Technical Specifications" (retrieved 2026-10-02). Introduced 10/4/1999, discontinued 7/19/2000; G3 at 350 or 400 MHz; two PC100 DIMM slots, 64-512 MB; VGA and two FireWire ports on DV and Special Edition; 150 W; 3.6 V lithium battery.
- ↑ 8.0 8.1 Apple, "iMac (Summer 2000) - Technical Specifications" (retrieved 2026-10-02). Introduced 7/19/2000, discontinued 2/22/2001; 350 to 500 MHz; up to 1 GB in two PC100 DIMM slots.
- ↑ Apple, "iMac (Early 2001) - Technical Specifications" (retrieved 2026-10-02). 400, 500 or 600 MHz; 512K backside or 256K on-chip L2 cache; two DIMM slots to 1 GB; Rage 128 Pro or Rage 128 Ultra.
- ↑ Apple, "iMac (Summer 2001) - Technical Specifications" (retrieved 2026-10-02). 500, 600 or 700 MHz with 256K L2; two DIMM slots to 1 GB; Rage 128 Ultra with 16 MB; 15-inch shadow-mask CRT, 13.8-inch viewable.
- ↑ Apple Computer, Apple Memory Guide (May 2000), hosted here as File:Apple Memory Guide (May 2000).pdf (see Apple Memory Guide). Power Macintosh pp. 28 and 32: original iMac (PDF p. 92); slot-loading iMac, DV and DV Special Edition (PDF p. 96).
- ↑ TinkerDifferent forum thread "iMac G3 service and rebuild (with MacEffects inner bezel)", August 2025 (retrieved 2026-10-02). Community repair report. Secondary source.