Josh: New page: Duo 250, specs from Apple SS and SP156, identifying a 250, display cautions

2026-10-02T08:37:13Z

New page: Duo 250, specs from Apple SS and SP156, identifying a 250, display cautions

New page

{{Infobox computer
| name = PowerBook Duo 250
| image = [[File:PowerBook Duo 250 logic board and display assembly (Service Source).png|260px|frameless]]
| caption = Apple's drawing of the Duo 250 logic board and display assembly (Service Source, PDF p. 209)
| manufacturer = Apple Computer, Inc.
| type = Subnotebook computer
| release_date = 21 October 1993
| discontinued = 1 May 1994
| price = US$2,500
| cpu = Motorola 68030 at 33 MHz; FPU only in a Duo Dock
| memory = 4 MB on the logic board; one Duo RAM card slot, to 24 MB
| rom = 1 MB
| storage = 200 MB 2.5-inch SCSI hard drive
| display = 9-inch active-matrix LCD, 640 × 400, 16 grey levels
| power = Type II NiMH battery; 24 V DC adapter
| dimensions = 1.4 × 10.9 × 8.5 in (H × W × D)
| weight = 4.2 lb (1.9 kg)
| os = System 7.1 to Mac OS 7.6.1
}}
The '''PowerBook Duo 250''' is a PowerBook Duo with a 33 MHz 68030 and a 9-inch active-matrix greyscale screen, introduced on 21 October 1993 with the [[PowerBook Duo 270c]] and sold until 1 May 1994. Apple's specification puts it beside the [[PowerBook Duo 230]] in every respect except the display, the 200 MB hard drive and the higher-capacity Type II battery.<ref name="sp156">Apple, [https://support.apple.com/kb/SP156 "Macintosh PowerBook Duo 250: Technical Specifications"] (retrieved 2026-10-02). 68030 at 33 MHz; FPU optional in dock; 25 W, 1.04 A; Duo NiMH Type II battery; 4 MB on board, one Duo RAM slot, 4-24 MB; 640 × 400 at 4 bits; introduced 10/21/1993, discontinued 5/1/1994; Gestalt ID 38; 4.2 lb; 1.4 H × 10.9 W × 8.5 D in; System 7.1 with PowerBook Duo Enabler v1.0, supported to 7.6.1; 200 MB SCSI hard drive.</ref><ref name="ss">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: specifications pp. 14-28; video symptom charts pp. 40-50; display housing pp. 145-153; 210/230/250/280 display cable pp. 154-166; 250 upgrade pp. 209-211; 280/280c upgrade pp. 216-226; exploded view p. 266.</ref> Low End Mac credits the active-matrix screen and the longer-running battery with the Duo line's rise in popularity.<ref name="lem250">Low End Mac, [https://lowendmac.com/1993/powerbook-duo-250/ "PowerBook Duo 250"] (retrieved 2026-10-02). Introduced 1993.10.21 at $2,500, discontinued 1994.05.01; improved battery lasting 2.5 hours; 4 MB to 24 MB; power supply M7783; upgrade path Duo 280. Secondary source.</ref>

== Specifications ==
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:70%;"
|+ '''Apple's specifications'''<ref name="ss" /><ref name="sp156" />
! Item !! PowerBook Duo 250
|-
| Processor || Motorola 68030, 33 MHz; 68882 FPU only in a Duo Dock
|-
| RAM || 4 MB soldered; one Duo RAM card of 4, 6, 8, 10, 12, 16 or 20 MB, to 24 MB, 70 ns<ref name="amg">Apple Computer, ''Apple Memory Guide'' (May 2000), hosted here as [[:File:Apple Memory Guide (May 2000).pdf]] (see [[Apple Memory Guide]]). PowerBook Duo 250, PDF p. 109: 4 MB soldered DRAM; cards of 4, 6, 8, 10, 12, 16 or 20 MB; 24 MB maximum; Apple supplies 4 MB and 8 MB cards.</ref>
|-
| Display || 9-inch (229 mm) active-matrix LCD, 640 × 400, 16 shades of grey, CCFL backlight
|-
| Storage || 200 MB 2.5-inch SCSI hard drive
|-
| Main battery || NiMH Type II, 1.5 Ah, 4/5 A size cells; about 2 to 3 hours
|-
| Power adapter || 24 V DC, 1.04 A (25 W)
|-
| Gestalt ID || 38
|}

== Identifying a Duo 250 ==
Apple sold a 250 upgrade kit for the 210 and 230, made up of a Duo 250 logic board and display assembly, and later a 280 kit that turned a 250 into a [[PowerBook Duo 280]]. Because of the second kit, Apple warns that the product label on the bezel does not identify a 250. The display cable does: the 210/230, 250 and 280 cables are all different, and Apple shows each one so a technician can tell them apart.<ref name="ss" /> The 280 kit supplied a new display cable for this reason. It is slightly longer than the 250 cable, and Apple says to leave the extra length loose.<ref name="ss" />

[[File:PowerBook Duo 210-230, 250 and 280 display cables (Service Source).png|thumb|center|420px|The 210/230, 250 and 280 display cables (Service Source, PDF p. 158)]]

== Display ==
The 250 has an active-matrix greyscale panel with a separate inverter board and brightness actuator inside the display housing.<ref name="ss" /> Two of Apple's cautions apply only to the 250 and 280:
* The inside of the 250/280 display housing has a copper surface that flakes or peels when touched, and the flakes can short the system (PDF p. 151).<ref name="ss" />
* Protective tape covers the inverter board; peeling it off can short the board (PDF p. 161).<ref name="ss" />

Apple's rule for dead pixels on the 250 and 280: replace the display if more than five pixels stay white, or if two or more such voids are within an inch of each other (PDF p. 50).<ref name="ss" /> Apple supplied 250 display assemblies, housings and cables to CPRC and international repairers only.<ref name="ss" /> MacDat found no electrolytic capacitors on the 250's LCD and had not checked its inverter board.<ref name="macdat250">MacDat, [https://macdat.net/cap_reference/apple/powerbook/duo250.html "PowerBook Duo 250 Capacitor Reference"] (retrieved 2026-10-02). Same logic board list as the 210/230: one 330 µF 16 V, three 100 µF 35 V, two 100 µF 25 V (100 µF 10 V on earlier boards), one 33 µF 25 V; the 250's LCD uses no electrolytic capacitors; inverter not checked; early trackballs have one 10 µF 6.3 V. Secondary source.</ref>

== Logic board ==
The 250 shares its logic board design with the 210 and 230, and MacDat gives the same seven-capacitor list for all three.<ref name="macdat250" /> Apple's exploded view lists service boards 661-1653 and 661-1672 for the 250.<ref name="ss" /> The capacitor positions are on [[PowerBook Duo Capacitor Replacement Guide]].

== Common problems ==
The faults are those of the other 68030 Duos: leaking electrolytics on the logic board, broken screw posts in the display housing, worn-out NiMH batteries and battery contacts out of alignment.<ref name="macdat250" /><ref name="ss" /> See [[PowerBook Duo Troubleshooting]] and [[PowerBook Duo General Maintenance]].

== Documentation ==
* [[PowerBook Duo 200 Series Service Source]]
* [[Apple Memory Guide]] (PDF p. 109)

== Related pages ==
* [[PowerBook Duo 210]], [[PowerBook Duo 230]], [[PowerBook Duo 270c]], [[PowerBook Duo 280]], [[PowerBook Duo 2300]]
* [[PowerBook Duo Capacitor Replacement Guide]]

== References ==
<references />

{{Navbox-AppleVintage|state=collapsed}}

[[Category:Apple Vintage Computers]]

PowerBook Duo 250 - Revision history

Josh: New page: Duo 250, specs from Apple SS and SP156, identifying a 250, display cautions