Apple is know for the torturesome detail it assign into the design and applied science of its production . But poppycock happens every once in a while — for model , when the Macintosh LC III was issue in 1993 , it actually had a error on its motherboard , but nobody could sustain the error for years and days — until now .
Doug Brown , a vintage Mac partizan , recently post on hisblogabout restoring a Macintosh Performa 450 , which is a repackaged Macintosh LC III . While replacing the original capacitors on its motherboard , Brown found that one of them was incorrectly set up because the positive and negative terminals were mislabeled .
It turn out that back in 2013 , Brown participated in aforum discussionabout this issue , but no one could confirm that this was an error on Apple ’s part . However , after visualize the takings in the Performa 450 and the right orientation in other Macintosh LCs , Brown believe that the serigraph that mark the depot on the Performa 450 / LC III motherboard was done in error .
When Brown removed the capacitors (C19, C21, and C22), he noticed that the C22 capacitor was mislabeled, resulting in an improper capacitor installation at the factory.
So why were those Macs still able to work out , and why did n’t orchard apple tree fix it ? consort to Brown , that erroneously installed capacitor was scab at 16V but only -5V move across it , which could have been enough to cause it to fail but not blow up or catch flak . Also , it was used only for the serial port and expansion circuit board , which likely were n’t used by owners of this type of Mac .
When Brown get rid of the condenser ( C19 , C21 , and C22 ) , he noticed that the C22 capacitor was mislabeled , resulting in an wrong electrical condenser installation at the factory .
Brown want to call attention to this because many computer regaining hobbyists replace quondam electrolytic capacitors with tantalum capacitors , which “ are not quite as forgiving when set up in reverse . ” So , if you ’re restoring an old LC III , be sure to set up the electrical condenser the correct way .
When Brown removed the capacitors (C19, C21, and C22), he noticed that the C22 capacitor was mislabeled, resulting in an improper capacitor installation at the factory.
