AppleColor Monitor 100: Fuzzy Display



Here are some things to check when the AppleColor Monitor 100 displays a
badly-focused image after components have been replaced:

1. Determine which revision of the main PCB you have, and make sure you're
replacing it with the same revision.  There are two revisions.  On a REV 0
logic board, CN17 (blue/white wire) plugs into the small board on the CRT. If
CN17 plugs into the main PCB in the upper left hand corner, you have a REV A
board.  If you need to  replace a REV 0 with a REV A, you must also change:

 A. Contrast/brightness control panel for one with the 1.8K resistor between
    the pots. Make sure that the value of the resistor on the Contrast
    Assembly is 1.8K NOT 18K Ohms. The color code for correct resistor is
    Brown/Gray/Red.

 B. The short interconnect cable must be changed. Following are the pinouts
    for both the REV 0 and REV A cables for the AppleColor Monitor 100:

    REV 0 (P/N 970-0999)      REV A (P/N 076-0196)
       DB15---Molex-8            DB15---Molex-8
         1---4                     1---1

         2---1                     2---2
         3---5                     3---3
         4---2                     4---4
         5---3                     5---5
         6---7                     6---6
         7---6                     7---7

2.  Swap the power supply.  A bad power supply can also cause a fuzzy
   display.


Published Date: Feb 18, 2012