Macintosh LC 475

Can probably be considered the fastest model of the pizza-box LC systems. The 475 is powered by a 25MHz Motorola 68LC040 processor, while the Macintosh LC III uses the Motorola 68030 though clocked as fast as 33MHz.

Video

Generally shipped with 512KB of VRAM via two SIMMs but can be expanded to 1MB which is required to achieve higher color and resolution.

Memory

The 475 has 4MB onboard memory and a single 72-pin RAM slot. The maximum memory capacity is assumed to be 36MB by using a 32MB SIMM, though larger capacity RAM sticks will likely work without issue.

Notes

• You may need to have a PRAM battery installed in this system for the video output to work properly.
• You can swap in a full 68040 processor as the original 68LC040 doesn't include the FPU.

Troubleshooting/Repair

Capacitor replacement (logic board)

The SMD capacitors on the logic board will most likely have already started leaking electrolyte out the bottom, and failing to replace them in a timely manner will result in further leakage with possible damage to nearby components. See below list of capacitors to replace:

• 9 x 47uf 16V
• 2 x 100uf 6.3V

Capacitor replacement (power supply unit)

A dead LC PSU can typically be revived by replacing all of the aluminum capacitors and cleaning up any leakage. Any working LC power supply should also be recapped as the capacitors will likely already be leaking due to component age, and the unit will eventually fail. The below list of capacitors should work for any of the TDK power supplies found in LC units.

• 1 x 180uf 385v
• 2 x 270uf 25v
• 3 x 1000uf 10v
• 1 x 8.2uf 50v
• 1 x 56uf 25v
• 1 x 47uf 25v
• 1 x 270uf 10v

Gallery

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See Also

• Apple Computer