Macintosh LC III and Performa 450: Difference between revisions

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|Picture = Macintosh LC III front.jpg
|Picture = Macintosh LC III front.jpg
|Release Year = 1993
|Release Year = 1993
|Mounting Technology = Through Hole (Analog Board, Logic Board), SMD (Logic Board)
|Mounting Technology = Through Hole (PSU), SMD (Logic Board)
|Capacitor Types = Aluminum Electrolytic
|Capacitor Types = Aluminum Electrolytic
|Leak Risk = High
|Leak Risk = High

Revision as of 23:16, 16 February 2022

This device is in the WorkNeeded:ReplacementParts category because it was flagged as missing information on replacement parts. If it has the original parts listed you may be able to search for replacements using the parametric searches available from parts distributors. If you have or make a list of replacement parts, please feel free to add them by copying the relevant table from EditorsToolbox:Tables
Macintosh LC III and Performa 450
Preliminary Information
Release Year 1993
Leak Risk High
Batteries Yes, Potentially Destructive
Mounting Technology Through Hole (PSU), SMD (Logic Board)
Capacitor Types Aluminum Electrolytic
Destructive Entry No

The Macintosh LC III (also branded as the Performa 450) was sold by Apple Computer from February 1993 to February 1994. Like all Macintoshes of its era, its original surface-mount electrolytic capacitors leak their contents and require replacing for both functionality and to protect critical traces on its circuit board from being eaten by electrolyte.

Known Issues

Maxell Battery "Bombs"

Causes
Apple placed a small lithium battery on the Macintosh LC III/Performa 450's Logic Board to power and preserve the contents of the Parameter RAM (PRAM). Apple used a number of different brands of battery for this purpose, one of which is Maxell. Maxell lithium batteries are notorious for rupturing in storage and spewing its highly corrosive contents all over the board.[1] If your Macintosh LC III/Performa 450 is still intact with its original PRAM battery, THE BATTERY MUST BE REMOVED IMMEDIATELY, even if it is not Maxell brand.
Solutions
Macintosh LC IIIs/Performa 450s with exploded PRAM batteries are pretty much irreparable, save for replacing the entire Logic Board.

Original Parts

From the now-defunct 68kMLA Wiki: "Some logic board revisions may have a different number of capacitors, so make sure to look first and verify this information."[2]

Revision 820-0650-A Logic Board

Capacitor Specifications and Footprint Information[2]
RefDes Qty Capacitance (µF) Voltage (V) Mount Size Type Brand
C8, C19, C20, C21, C22 5 47 16 SMD Aluminum Electrolytic Unbranded
C2, C4, C5, C7, C18 5 10 16 SMD Aluminum Electrolytic Unbranded
C13 1 100 6 SMD Aluminum Electrolytic Unbranded

References

  1. "Macintosh LC III Maxell Battery damage - fixable?" 68kMLA.
  2. 2.0 2.1 "Capacitor Replacement". 68kMLA Wiki. Archived from the original on August 24, 2017. Content licensed under GNU FDL.