The Problem My Macintosh Classic II suffers from an issue where the display CRT goes dim after a few minutes on a cold boot. Every time it happens, I need to crank up the cut-off and brightness pot behind the machine to show the image. The Analyze At first, I thought it must be the brightness issue, so I searched for the Macintosh Classic analog board schematic to check the brightness line. I found the schematic from Bomarc, and the schematic is suitable with my board, since there are two analog board versions. I started to suspect the resistors and potentiometer on the brightness line. This Macintosh version has software-controlled brightness, so the analog board will get a 22.25 kHz square wave PBM signal from the logic board to control the brightness. I checked and replaced some resistors and cleaned the potentiometer, but nothing seems to work. The signal is there, and no sign of degradation that makes the screen dim after a few minutes. Brightness Line So I suspec...
iWoz Book Cover An inspirational book and going to be one of my favorite books. An autobiography by Steve Wozniak, from when he was a child and became an inspirational engineer (of course billionaire) after he founded Apple Computer. As an engineer, I love Steve Wozniak more than Steve Jobs. He is a genius who always finds a simpler way to solve a problem, from simplifying an arcade game, standardizing a home computer with a monitor, designing a simple disk drive controller, innovating with universal remote control, etc. A very recommended book, you can read some of the sample pages here .