PowerBook Duo 280
.jpg) | |
| PowerBook Duo 280c (Alexander Schaelss, Wikimedia Commons, CC BY-SA 3.0) | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Subnotebook computer |
| Released | 16 May 1994 |
| Discontinued | 14 November 1994 (280); 27 January 1996 (280c) |
| Intro price | US$2,600 (280); US$3,750 (280c) |
| CPU | Motorola 68LC040 at 33 MHz (66 MHz internal); no FPU |
| Memory | 4 MB on the logic board; one Duo RAM card slot, to 40 MB |
| Storage | 240 MB (280) or 320 MB (280c) 2.5-inch SCSI hard drive |
| Display | 280: 9-inch active-matrix greyscale, 640 × 400; 280c: 8.4-inch colour active-matrix, 640 × 480 at 256 colours or 640 × 400 at thousands |
| Sound | — |
| ROM | 1 MB |
| Power | Type III NiMH battery; 24 V DC adapter (25 W for the 280, 36 W for the 280c) |
| Dimensions | 1.4 in (280) or 1.5 in (280c) × 10.9 × 8.5 in |
| Weight | 4.2 lb (280); 4.8 lb (280c) |
| OS / Firmware | System 7.1.1 to Mac OS 8.1 |
The PowerBook Duo 280 and PowerBook Duo 280c are the 68LC040 PowerBook Duos, introduced on 16 May 1994 to replace the PowerBook Duo 250 and PowerBook Duo 270c. They share a logic board, a 33 MHz 68LC040 with no floating-point unit, a 40 MB memory ceiling and the Type III battery. The 280 has a greyscale active-matrix screen; the 280c has a colour one and is thicker and heavier. The 280c was the last 68k Duo, sold until January 1996.[1][2] The PowerBook Duo 2300 followed in August 1995.[3]
Specifications
| Item | Duo 280 | Duo 280c |
|---|---|---|
| Processor | Motorola 68LC040, 66/33 MHz, 8 KB cache, no FPU | |
| RAM | 4 MB soldered; one Duo RAM card, to 40 MB with a 36 MB card; 70 ns[5] | |
| Display | 9-inch backlit active-matrix greyscale, 640 × 400, 16 shades | 8.4-inch backlit active-matrix colour, 640 × 480 at 256 colours or 640 × 400 at thousands |
| Hard drive | 240 MB | 320 MB |
| Main battery | NiMH Type III, 1.6 Ah; about 2 to 3 hours | |
| Power adapter | 24 V DC, 1.04 A (25 W) | 24 V DC, 1.5 A (36 W) |
| Height and weight | 1.4 in; 4.2 lb | 1.5 in; 4.8 lb |
| Gestalt ID | 102 | 103 |
Low End Mac gives the launch prices as US$2,600 and US$3,750 and lists the M7783 adapter for the 280 and the M2693 for the 280c.[6] Apple gives the 280c display as 8.4 inches against 9 inches for the 270c, yet owners of both report the same Sharp LQ9D041 panel; MacDat gives one capacitor list for the two.[4][7][8]
Hardware
Logic board
Apple's service board for both models is 661-0051.[4] Console5 lists its electrolytics with designators: C2 47 µF 35 V; C3, C7, C8 and C9 100 µF 35 V; C6 100 µF 25 V; C72 33 µF 25 V. This matches MacDat's count.[9][7]
.jpg)
Apple fits a large foam heatsink pad under the CPU stiffener tab of a 280 or 280c, where the 210, 230, 250 and 270c take a small one. A replacement stiffener needs the right pad.[4]
Displays
The 280's greyscale panel and its inverter carry no electrolytic capacitors, according to MacDat.[7] The 280c's colour panel is described by nvdeynde on 68kMLA as full of small surface-mount electrolytics, some already leaking or with high ESR.[10] jmacz recapped a 280c panel with polymer parts of the original size and later broke one solder joint by gripping the lid hard, and suggested low-profile polymer tantalums instead. The same machine had a high-pitched whine from the inverter's coils, which stopped once the coils were coated with thin superglue.[8]
The 280 kit for a 250 includes a new display cable, slightly longer than the 250's; Apple says to leave the extra length loose. A 270c becoming a 280c keeps its own cable.[4]
Common problems
- Leaking electrolytics in the power circuit. FlyingToaster's 280c ticked from the DC-DC circuit and never worked again, and techknight warned that this damage is usually terminal.[10] See PowerBook Duo Capacitor Replacement Guide.
- Broken screw posts and a broken speaker mount inside the display housing; jmacz printed replacement stand-offs and epoxied them in.[8]
- A gummed-up trackball, cleaned with isopropyl alcohol.[8]
- Mushy or dead keys; cleaning the contacts and relubricating the key stems helped, but did not cure every key.[8]
See PowerBook Duo Troubleshooting and PowerBook Duo General Maintenance. Replacing the hard drive with a SCSI emulator needs a new mount, because the drive fixes from the side; jmacz published a 3D model for one.[8]
Upgrades
Apple's 280/280c kit upgraded a 250 to a 280 or a 270c to a 280c. It was a 280 case bottom, logic board and CPU stiffener assembly with a Type 3 battery and a 36 W adapter.[4] The 2300 kit later replaced the same assembly with a PowerPC board, and the 280c display then connects to the 2300c board's TFT connector, J7.[4]
Documentation
Related pages
References
- ↑ 1.0 1.1 Apple, "Macintosh PowerBook Duo 280: Technical Specifications" (retrieved 2026-10-02). 68LC040 at 66 MHz (33 MHz bus), 8K L1 cache, no FPU; 25 W, 1.04 A; Duo NiMH Type III battery; 4 MB on board, 4-40 MB; 640 × 400 at 4 bits; introduced 5/16/1994, discontinued 11/14/1994; Gestalt ID 102; 4.2 lb; 1.4 in high; System 7.1.1 with PowerBook Duo Enabler v2.0, supported to 8.1; 240 MB hard drive.
- ↑ 2.0 2.1 Apple, "Macintosh PowerBook Duo 280c: Technical Specifications" (retrieved 2026-10-02). 68LC040 at 66 MHz, no FPU; 36 W, 1.5 A; Duo NiMH Type III battery; 4 MB on board, 4-40 MB; 640 × 400 at 16 bits, 640 × 480 at 8 bits; introduced 5/16/1994, discontinued 1/27/1996; Gestalt ID 103; 4.8 lb; 1.5 in high; System 7.1.1 with PowerBook Duo Enabler v2.0, supported to 8.1; 320 MB hard drive.
- ↑ Wikipedia, "PowerBook Duo" (retrieved 2026-10-02). Duo 280 and 280c released May 1994 as 68LC040 replacements for the 250 and 270c, supporting 40 MB; 280c shipped with the Type III battery; Duo 2300c August 1995. Used for history only.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Apple Computer, PowerBook 200 Series Service Source, hosted here as File:PowerBook Duo 200 Series Service Source.pdf (see PowerBook Duo 200 Series Service Source). PDF page numbers: processor and memory pp. 14-17; display pp. 22-23; electrical pp. 24-25; physical p. 26; CPU stiffener heatsinks pp. 132-134; 280/280c upgrade pp. 216-226; 2300 upgrade pp. 227-239; exploded view p. 266.
- ↑ Apple Computer, Apple Memory Guide (May 2000), hosted here as File:Apple Memory Guide (May 2000).pdf (see Apple Memory Guide). PowerBook Duo 280/280c, PDF p. 111: 4 MB soldered; cards of 4, 6, 8, 10, 12, 16, 20, 24 or 36 MB; 40 MB maximum with a third-party 36 MB card; Apple supplies an 8 MB card.
- ↑ Low End Mac, "PowerBook Duo 280" and "PowerBook Duo 280c" (retrieved 2026-10-02). 280 introduced 1994.05.16 at $2,600, discontinued 1994.11.14, power supply M7783; 280c introduced 1994.05.16 at $3,750, discontinued 1996.01.27, 8.4-inch display, power supply M2693. Secondary source.
- ↑ 7.0 7.1 7.2 MacDat, "PowerBook Duo 280c Capacitor Reference" and "PowerBook Duo 280 Capacitor Reference" (retrieved 2026-10-02). Logic board (both): four 100 µF 35 V, one 100 µF 25 V, one 47 µF 35 V, one 33 µF 25 V; 280c Sharp LQ9D041 LCD: fifteen electrolytics; 280c inverter: one 10 µF 35 V; the 280's LCD and inverter have no electrolytics. Logic board photo by jmacz. Secondary source.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 68kMLA forum thread "Powerbook Duo 280c + Accessories Maintenance", jmacz, March 2025. Full recap of a 280c (logic board, LCD, inverter, power adapter); inverter coil whine stopped with superglue; broken display stand-offs and speaker mount; trackball cleaning; ZuluSCSI with a 3D-printed side mount; keyboard cleaning. Community repair report.
- ↑ Console5 TechWiki, "Macintosh PowerBook 280c" (retrieved 2026-10-02). Cap list: C2 47 µF 35 V; C3 100 µF 35 V; C6 100 µF 25 V; C7, C8, C9 100 µF 35 V; C72 33 µF 25 V. Secondary source.
- ↑ 10.0 10.1 68kMLA forum thread "Notice to Powerbook Duo Users!", techknight, nvdeynde, FlyingToaster and others, February-March 2012. Leaking DC-DC electrolytics on a 270c; a 280c that ticked from the DC-DC circuit and then died; leaking and high-ESR capacitors behind the 280c LCD. Community repair report.