Macintosh LC III
The Macintosh LC III is an entry-level 68030-based Macintosh desktop that was released in February 1993. It was significantly faster than the LC II that it would shortly replace, as it was based on a faster architecture. A faster model, the LC III+, was released outside of the US. It ran at 33MHz instead of the 25 that the regular LC III ran at. Most "LC III+" units around today are normal LC IIIs that have been overclocked, as this is quite easy to do.
Photo credit - Stephen Edmonds - CC BY SA
Specifications
| Spec | Details |
|---|---|
| Release Date | February 1993 |
| Discontinuation Date | February 1994 |
| Processor | Motorola 68030 @25MHz FPU: Optional Bus Speed: 25MHz |
| RAM | 1x 72-pin SIMM Slot - 4MB Standard - 36MB Maximum |
| Hard Disk | 3.5" SCSI - 80MB Standard |
| Graphics | 512 or 768KB VRAM |
| Audio | Internal Speaker |
| Internal Drives | Auto-inject 3.5" 1.44MB Floppy Drive |
| Expansion | 1x LC III PDS Slot |
| Networking | None |
| Other I/O | - 1x ADB - 2x Serial - 1x DB25 SCSI - 1x DB15 Video Out - 1x Line Out - 1x Mic In |
| PRAM Battery | 1/2AA Lithium |
| Original Mac OS | System 7.1 |
| Maximum Mac OS | Mac OS 7.6.1 |
Upgrades
CPU Upgrade
68040 CPU upgrade cards were available.
SSD Upgrade
Check our page on SCSI SSD replacements for more info.
Resources
 Service Manual |
 Logic Board Schematic |
Capacitor Reference |
|---|
Common Faults & Maintenance
PRAM Battery Leaks
The Macintosh LC III's Lithium PRAM battery is highly prone to leaking and should absolutely be removed. The LC III does not require a working battery to start.
Capacitors
The LC III's logic board has several surface-mount electrolytic capacitors on it that leak corrosive fluid with age. These must be replaced for reliable operation.
The LC III's power supply also usually needs recapping for the same reasons - especially if you have the TDK PSU, which used ELNA brand caps.
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 LC III'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 later Macs.
Page last updated (MM/DD/YYYY): 03/11/2025
Update Reason: page rewritten
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