Macintosh IIx
The Macintosh IIx was released in 1988 as an upgraded version of the original Mac II. It shared the same case, but used a faster 68030 processor.
Specifications
| Spec | Details |
|---|---|
| Release Date | September 1988 |
| Discontinuation Date | October 1990 |
| Processor | Motorola 68030 @16MHz FPU: Yes Bus Speed: 16MHz |
| RAM | 8x 30-pin SIMM Slots - 1 or 4MB Standard - 128MB Maximum |
| Hard Disk | SCSI - 40 or 80MB Standard |
| Graphics | 256 or 512KB |
| Audio | Internal Speaker |
| Internal Drives | 2x Auto-inject 3.5" 1.44MB Floppy Drives |
| Expansion | 6x NuBus Slots |
| Networking | None |
| Other I/O | - 2x ADB - 2x Serial - 1x DB25 SCSI - 1x DB15 Video Out (on NuBus video card) - 1x Line Out |
| PRAM Battery | Two 1/2AA Lithium Batteries |
| Original Mac OS | System 6.0.1 |
| Maximum Mac OS | Mac OS 7.5.5 |
Upgrades
CPU Upgrade
Faster 68030 and 68040 CPU upgrade cards were available.
SSD Upgrade
Check our page on SCSI SSD replacements for more info.
Resources
 Service Manual |
Capacitor Reference |
|---|
Common Faults & Maintenance
PRAM Battery Leaks
The Macintosh IIx used two 1/2AA Lithium batteries - one as the PRAM battery, and the "startup battery", which was required to jump-start the soft power circuit in the Macintosh. If this battery is dead, the Mac II won't power on. Early production Mac IIxs used soldered 3V batteries from Varta, which rarely leak. Later production units switched to socketed 3.6V batteries, which used a different chemistry that is much more prone to leakage. The batteries should be removed and replaced regardless.
Capacitors
The IIx motherboard uses many surface mount electrolytic capacitors, which always leak with age, causing corrosion to the motherboard. They must be replaced for reliable operation.
The power supplies in the Mac IIx are generally reliable, but some of them have Rifa filter caps inside which can explode, releasing a bunch of nasty smoke.
Other Notes
Most original SCSI hard drives for these have gone bad, especially those made by Quantum, which suffer from sticky rubber bumpers in the head assembly.
The floppy drives in these often suffer from eject motor failures due to a gear that falls apart with age. This gear can be replaced without too much trouble.
The Mac IIx's case yellows with age. A retrobrite process can be used to correct this, if it bothers you. The plastic is not nearly as brittle as Macs from the 90s though.
Page last updated (MM/DD/YYYY): 03/03/2025
Update Reason: page rewritten
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