Path: utzoo!attcan!uunet!mailrus!jarvis.csri.toronto.edu!ephemeral.ai.toronto.edu!dudek
From: dudek@ai.toronto.edu (Gregory Dudek)
Newsgroups: comp.sys.mac.hardware
Subject: Re: screen flickers on a plus
Message-ID: <89Nov19.172725est.11130@ephemeral.ai.toronto.edu>
Date: 19 Nov 89 22:28:43 GMT
References: <4963@elroy.uh.edu> <9849@june.cs.washington.edu>
Organization: Department of Computer Science, University of Toronto
Lines: 24

In article <9849@june.cs.washington.edu> gordon@june.cs.washington.edu.cs.washington.edu (Gordon Davisson) writes:
>In article <4963@elroy.uh.edu> CHEE77@elroy.uh.edu (Fred Schulz) writes:
>>What would cause the screen to flicker on and off. After my plus has
>>been on for a while, tapping the sid will cause the screen to go off, or
>>on. I sure don't want to take it to a dealer to have the analog board
>>replaced. I've heard mention of a cracked solder joint, but saw no
>>obvious suspects when I opened it up.
>>
>>Any suggestions? Thanks.
>
>The solder joint you're looking for is on the connector for the cable to
>the motherboard.  It's a 10-pin connector near the middle of the analog
>board.  It has 9 pins in a group, then a gap, then one by itself (toward
>the front of the machine).  The isolated pin is almost certainly your
>problem.  The cracks I see here are usually very thin and can be hard
>to see, especially if the solder is shiny.
>
  Another common place for a bad solder joint (I had one) is (apparently)
right under the small coil near the C1 capacitor.  On my board, the
paper board covering under the coil was badly browned from the heat 
from the coil and the weaked solder joint was clearly visible.
  This coil in near the rear of the board (as opposed to the connector above).
   
   Greg Dudek