Macintosh LC
The Macintosh LC (Low-cost color) is an entry-level 68020-based Macintosh desktop that was released in October 1990. It was the first Macintosh desktop to use the "pizza box" form factor, and one of just two Macs to use the 68020 processor.
Specifications
| Spec | Details |
|---|---|
| Release Date | October 1990 |
| Discontinuation Date | March 1992 |
| Processor | Motorola 68020 @16MHz FPU: No Bus Speed: 16MHz |
| RAM | 2x 30-pin SIMM Slots - 2 or 4MB Standard - 10MB Maximum |
| Hard Disk | 3.5" SCSI - None, 40MB, or 80MB Standard |
| Graphics | 256 or 512KB VRAM |
| Audio | Internal Speaker |
| Internal Drives | 1 or 2 Auto-inject 3.5" 1.44MB Floppy Drives |
| Expansion | 1x LC 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 6.0.7 |
| Maximum Mac OS | Mac OS 7.5.5 |
Upgrades
CPU Upgrade
68030 and 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's Lithium PRAM battery is highly prone to leaking and should absolutely be removed. The LC does not require a working battery to start.
Capacitors
The LC'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'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'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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