Power Macintosh G3 (Beige)
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| Power Macintosh G3 desktop (Danamania, Wikimedia Commons, CC BY-SA 2.5) | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Desktop computer (desktop and minitower enclosures) |
| Released | 15 November 1997 |
| Discontinued | January 1999 |
| CPU | PowerPC G3 (750) at 233, 266 or 300 MHz on a removable processor module; 512 KB backside L2 cache |
| Memory | 32 MB SDRAM standard; three 168-pin DIMM slots |
| Storage | 4 or 6 GB ATA hard disk; 24x CD-ROM or 2x DVD-ROM; 1.4 MB floppy drive; optional Zip drive |
| Display | Built-in ATI graphics with 2 MB SGRAM, expandable to 6 MB |
| Sound | 16-bit stereo on the Apple I/O card in the PERCH slot |
| ROM | 4 MB on a ROM DIMM |
| Power | 230 W (desktop) or 240 W (minitower); manual 115/230 V switch |
| Dimensions | Desktop 6.15 × 14.37 × 16.93 in (15.6 × 36.5 × 43.0 cm) |
| Weight | Desktop 22 lb (9.97 kg); minitower 33.1 lb |
| OS / Firmware | Mac OS 8.0 to Mac OS X 10.2.8 |
| Predecessor | Power Macintosh 7300, Power Macintosh 8600, Power Macintosh 9600 |
| Successor | Power Macintosh G3 (Blue and White) |
The Power Macintosh G3 in its beige enclosures was Apple's first Macintosh with the PowerPC G3 processor. Apple sold it from November 1997 in a desktop case and a minitower case, both built around the same logic board, and from April 1998 in the education-only Power Macintosh G3 All-in-One, which uses that board as well.[1][2] Apple's specification pages give 15 November 1997 as the introduction date of both the desktop and the minitower; Wikipedia and Low End Mac give the announcement date, 10 November 1997.[3][4] It replaced the Power Macintosh 7300, Power Macintosh 8600 and Power Macintosh 9600.[4]
Models
[edit | edit source]| Item | Desktop | Minitower |
|---|---|---|
| Apple model number | M3979[4] | M4405[4] |
| Power supply (Apple specification pages) | 230 W, 8.0 A[3] | 240 W, 8 A[5] |
| Logic board jumper J28 | Over the pins marked "Mac" | Over the pins marked "PS"[1] |
| Maximum RAM (Apple specification pages) | 192 MB[3] | 384 MB[5] |
| Size (H × W × D) | 6.3 × 14.4 × 16.9 in[3] | 15.2 × 9.6 × 17.8 in[5] |
| Weight | 22 lb[3] | 33.1 lb[5] |
The Service Source gives 384 MB as the maximum for the board in either case.[1] Low End Mac gives the same 192 MB and 384 MB limits as Apple's pages, puts the difference down to the desktop case needing low-profile DIMMs, and reports that both cases take three 256 MB DIMMs built with 128 Mb chips (768 MB).[4]
Specifications
[edit | edit source]| Item | Specification |
|---|---|
| Processor | PowerPC G3 at 233, 266 or 300 MHz; 64-bit 66 MHz processor bus |
| Cache | 512 KB level 2 cache on the processor module |
| RAM | 32 MB standard, expandable to 384 MB; 168-pin, 64-bit, 3.3 V unbuffered SDRAM DIMMs, 70 ns or faster |
| ROM | 4 MB on a 160-pin ROM DIMM |
| Video | 2 MB SGRAM, expandable to 4 or 6 MB with a 144-pin 3.3 V SGRAM SO-DIMM; 640 × 480 to 832 × 624 at 32 bits, 1024 × 768 to 1600 × 1200 at 16 bits |
| Expansion | Three PCI slots (6.88 or 12.283 in cards; three 15 W or two 25 W cards); PERCH slot for the Apple I/O card; 112-pin modem slot |
| Ports | External SCSI (DB-25), two GeoPort serial, ADB, 10BASE-T Ethernet, monitor port, sound in and out on the I/O card |
| Storage | 4 or 6 GB ATA hard disk (4 or 9 GB Ultra Wide SCSI optional); 24x ATAPI CD-ROM or 2x DVD-ROM; 1.4 MB SuperDrive; optional SCSI or ATAPI Zip drive depending on logic board version |
| Electrical | 100-130 V or 200-240 V by voltage switch, 50-60 Hz; 230 W maximum continuous, 290 W peak input |
| Desktop size and weight | 6.15 × 14.37 × 16.93 in (15.6 × 36.5 × 43.0 cm); 22 lb (9.97 kg) |
| Software | Original board: Mac OS 8.0 or later with the appropriate enabler; version 2 board: Mac OS 8.1 or later with enabler 777 |
Apple's 1998 developer note rates the desktop and tower supply at 161 W continuous DC output and 210 W peak for 12 seconds at startup.[6]
Hardware
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Logic board
[edit | edit source]The desktop and minitower use the same logic board, set for each case by two jumpers: J28 for the power supply and J16 for the processor speed.[1] Apple's code name for it is Gossamer, and the board is 820-0991 (revisions -A and -B on Console5's list).[4][7] The All-in-One carries the same board: Apple's All-in-One Service Source lists the Version 2 board, 661-2063, with J28 set for the All-in-One supply, and a 68kMLA member found the same 820-0991-A number on the boards of his All-in-One and his desktop.[8][9] Apple's exploded view lists the logic board as 661-1302, and a Hot Issue names a version 2 board, 661-2063, whose hard drives shipped formatted HFS+.[1]
Apple's developer note separates the boards by ROM: the original board has ROM subversion V4.0 F2, and the later boards have V4.5 F1 or V4.5 F2 and carry the ATI Rage Pro graphics controller.[6] Low End Mac lists the three ROMs as $77D.40F2, $77D.45F1 and $77D.45F2.[4] Wikipedia and Low End Mac say early machines, with the Revision A ROM and Rev. 1 board, do not support a second (slave) device on an ATA channel, and later ones do.[2][4]
Processor module and voltage regulator
[edit | edit source]The processor and its 512 KB cache sit on a module in a ZIF socket. A colour-coded jumper block at J16 sets the board for the module: red for 233 MHz, white for 266 MHz and black for 300 MHz. A warranty sticker covers it, and a missing or wrong block leaves the computer unable to start.[1] Apple's part numbers are 661-1460, 661-1461 and 661-2059 for the modules and 076-0716, 076-0717 and 076-0737 for the jumper kits.[1]
The processor's core supply comes from a plug-in voltage regulator card, 922-3292, which Apple supplies with a replacement logic board and separately.[1] Low End Mac, citing Macworld, says machines with a Royal Technology regulator need it replaced before a processor upgrade is fitted.[4]
I/O card and memory
[edit | edit source]Sound, and on some models video input and output, is on an Apple I/O card in the PERCH slot. The computer starts without the card but does not work properly.[1] Wikipedia names the cards Whisper (audio), Wings (audio and video) and Bordeaux (DVD-Video and audio/video).[2] No memory is soldered to the board; at least one SDRAM DIMM must be fitted. Do not fit DIMMs from older Macintosh models, which fit the sockets but do not work, and use only SGRAM SO-DIMMs for video memory.[1]
Power supply
[edit | edit source]The desktop and minitower supplies differ, and J28 tells the board which one is fitted: "Mac" for the desktop and "PS" for the minitower. Replacement boards come set for the desktop.[1] 68kMLA members describe the minitower supply as ATX-type and the desktop one as Apple's own design.[10] Both supplies have a manual 115/230 V switch on the back.[1]
Known faults
[edit | edit source]- Fan running but no chime, no drive activity, no front LED and no video. Apple's Hot Issue for this points at a badly seated or failed voltage regulator; reseat or replace it before replacing the logic board.[1]
- Scrambled PRAM after a battery change or a flat battery. 68kMLA members report that the normal Command-Option-P-R reset often does not clear it on these machines and that unplugging, removing the battery and pressing the power button does.[11]
- Electrolytic capacitors on the logic board and the voltage regulator card. One owner found some leakage under a few board capacitors when recapping a minitower that had stopped starting.[12] See Power Macintosh G3 (Beige) Capacitor Replacement Guide.
- A single ATA device fitted to the second connector (J10) with J9 empty may not boot; fit a lone device to J9.[1]
- CD-ROM trays in the desktop that fail to eject. Apple's fix is foam bumpers, part 922-3554, on the back of the drive carrier.[1]
- HFS+ formatted drives damaged by Norton Utilities 3.5.1 and earlier.[1]
Fault-finding is on Power Macintosh G3 (Beige) Troubleshooting.
Maintenance and repair
[edit | edit source]- Power Macintosh G3 (Beige) General Maintenance
- Power Macintosh G3 (Beige) Troubleshooting
- Power Macintosh G3 (Beige) Capacitor Replacement Guide
Documentation
[edit | edit source]- Power Macintosh G3 Desktop and Minitower Service Source: Apple's service manual.
- Power Macintosh G3 Documentation: the 1998 developer note and the Gossamer logic board schematic.
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Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 Apple Computer, Power Macintosh G3 Desktop Service Source (covers the desktop and minitower), hosted here as File:Power Macintosh G3 Desktop and Minitower Service Source.pdf (see Power Macintosh G3 Desktop and Minitower Service Source). PDF page numbers: Hot Issues pp. 3-13 (shared logic board p. 4; J28 and J16 jumpers p. 5; warranty sticker and voltage switch p. 6; voltage regulator and I/O card p. 7; ROM DIMM and SDRAM p. 8; SGRAM and EIDE bus p. 9; master/slave support p. 10; CD-ROM ejection p. 11; HFS+ and logic board 661-2063 p. 12; power-on issue p. 13); Cuda chip p. 62; Resetting the Logic Board pp. 63-64; Voltage Switch pp. 73-75; Logic Board diagram p. 85; Specifications pp. 96-106; Power Supply take-apart pp. 148-151; Battery pp. 171-173; Troubleshooting pp. 218-254; Exploded View p. 256.
- ↑ 2.0 2.1 2.2 Wikipedia, "Power Macintosh G3" (retrieved 2026-10-02). Introduced 10 November 1997; desktop, mini tower and All-In-One models; desktop enclosure from the Power Macintosh 7300; desktop updated August 1998 with the 233 MHz model dropped; Gossamer logic board; Revision A ROMs without IDE slave support and with Rage II+ video, Revision B with slave support and Rage Pro, Revision C with Open Firmware 2.4 and Rage Pro Turbo; Whisper, Wings and Bordeaux personality cards; replaced by the Blue and White model in January 1999. History only.
- ↑ 3.0 3.1 3.2 3.3 3.4 Apple, "Power Macintosh G3 Desktop - Technical Specifications" (retrieved 2026-10-02). G3 at 266 MHz (300 MHz option); 230 max watts, 8.0 A, 100-240 V; battery 3.6 V lithium; 3 PCI slots and 1 comm slot; 3 DIMM slots, 32-192 MB, 10 ns; 2 MB SGRAM expandable to 6 MB; introduced 11/15/1997, discontinued 1/1/1999; original system 8.0; Gestalt ID 510; ROM ID $0770, 4 MB; 22 lb; 6.3 × 14.4 × 16.9 in; 4 GB minimum hard disk, IDE; 24x CD.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Low End Mac, "Beige Power Mac G3 (1997)" (retrieved 2026-10-02). Announced 10 November 1997, discontinued 14 December 1998; code name Gossamer; model numbers M3979 (desktop) and M4405 (minitower); early machines with Rev. 1 boards and Rev. A ROMs cannot use slave drives; ROM versions $77D.40F2, $77D.45F1 and $77D.45F2; desktop configurable to 192 MB and minitower to 384 MB, both able to use 3 × 256 MB; desktop needs low-profile DIMMs (1.15 in maximum); 256 MB DIMMs must use 128 Mb chips; machines with a Royal Technology voltage regulator must have it replaced before a CPU upgrade (citing Macworld, 2000); PRAM battery 3.6 V half-AA; price about US$2,400 at launch. Secondary source.
- ↑ 5.0 5.1 5.2 5.3 Apple, "Power Macintosh G3 Mini Tower: Technical Specifications" (retrieved 2026-10-02). G3 at 266 MHz (300 MHz option); 240 max watts, 8 A; battery 3.6 V lithium; 3 PCI slots and 1 comm slot; 3 DIMM slots, 32-384 MB; DIMMs 3.3 V unbuffered, 64-bit, 168-pin, 100 MHz/10 ns or faster; introduced 11/15/1997, discontinued 1/1/1999; Gestalt ID 510; 33.1 lb; 15.2 × 9.6 × 17.8 in; 6 GB minimum hard disk; includes a Zip drive.
- ↑ 6.0 6.1 Apple Computer, Power Macintosh G3 Computers developer note ("Includes Power Macintosh G3 All-in-one, desktop, and minitower computers", revised 8/13/98), hosted here as File:Power Macintosh G3 Computers Developer Note (1998).pdf (see Power Macintosh G3 Documentation). PDF p. 14: original logic board ROM subversion 0x40F2 (V4.0 F2); enhanced boards 0x45F1 or 0x45F2 with the ATI Rage Pro, the 0x45F2 ROM shipping from August 1998; May 1998 changes made for the All-in-one rolled across the line. Power supply section: voltage switch for 100-130 V or 220-270 V, unswitched monitor socket (PDF p. 34). PDF p. 60: AC input 960 VA continuous, 1070 VA peak. PDF p. 61: DC output 161 W continuous, 210 W peak for 12 seconds at startup; +5 V trickle 0.1 A; maximum 500 mA for all ADB devices.
- ↑ Console5 Tech Wiki, "Macintosh G3" (retrieved 2026-10-02, via the wiki's raw page). Capacitor list "confirmed for 820-0991-A / 820-0991-B"; switch board capacitors for the -A desktop and -B server. Secondary source.
- ↑ 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 p. 126: jumper J28 sets the logic board for the All-in-One supply, which differs from the desktop and minitower supplies; Exploded View p. 185: "Logic Board, PMG3, 3-Slot" 661-2063.
- ↑ 68kMLA forum thread "G3 AIO Power Supply Jumper", September 2012. mcdermd: a Mac/PS2 power supply jumper above the PCI slots near the Cuda reset button; the board in his beige G3 desktop is the same part (820-0991-A) as the one in the All-in-One, with the same jumper and an unpopulated cache header; coius moved an AIO board into a minitower. Community experience.
- ↑ 68kMLA forum thread "G3 beige DT and Tower power supplies different?", September-October 2007. A desktop board moved into a minitower case did nothing until the PS/2-Mac jumper was moved; Unknown_K: the tower has the ATX supply, the desktop a custom one; alk: with the jumper in the PS/2 position the pinout is ATX; MacJunky: J28 is beside the outermost PCI slot near the Cuda reset switch. Community experience.
- ↑ 68kMLA forum thread "No video after PRAM battery replaced (Beige G3 Tower)", January 2015. jdmoser: after a PRAM battery change the ATI card gave no video while the onboard video worked; Macdrone: the beige G3 is "a beast with the pram battery issue"; unplug, remove the battery, press the power button, refit the battery and boot from a CD with C; the normal zap did not work for him on the AIO, tower or desktop. Community experience.
- ↑ 68kMLA forum thread "Beige PowerMac G3 Capacitor Replacement", August 2023 to August 2024. shadedream: logic board 16 × 47 µF 16 V, 5 × 100 µF 6.3 V (one of them on the personality card) and 1 × 10 µF 16 V; voltage regulator board 4 × 1500 µF 6.3 V through-hole (Nichicon UPW low-impedance on his); some leakage under a few caps; 3lectr1cPPC: the tower, desktop and AIO boards are the same; Phipli: caps still good on his beige G3s, preventive recapping not needed; croissantking: his regulator labelled Switch Power, Apple P/N 614-0081, has 4 × 680 µF 10 V. Community repair report.