Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!swrinde!gem.mps.ohio-state.edu!ctrsol!lll-winken!sun-barr!newstop!sun!amdcad!user7
From: user7@amdcad.AMD.COM (Unix class)
Newsgroups: comp.sys.mac.hardware
Subject: Re: MacPlus video linearity question.
Keywords: video, linearity, macplus
Message-ID: <28092@amdcad.AMD.COM>
Date: 18 Nov 89 03:16:27 GMT
References: <4912@frosted-flakes.ai.mit.edu> <3525@alliant.Alliant.COM>
Reply-To: user7@amdcad.UUCP (Unix class)
Distribution: comp.sys.mac.hardware
Organization: Advanced Micro Devices
Lines: 23

In article <3525@alliant.Alliant.COM> eaw@alliant.Alliant.COM (Eric Woudenberg) writes:
>I have a MacPlus that at one time had a capacitor on it's video board
>go bad.  I've replaced the capacitor and things have been working fine
>for at least a year.  I noticed soon after I had repaired it that the
>video was slightly trapezoidal, with the left edge of the screen being
>smaller than the right edge.  I looked at my Father's machine (which
>has also had a video failure and repair) and noticed that his was also
>trapezoidal, only with the left edge bigger than the right.
>

I'll make a guess and say that it sounds like as if the capacitor is not
the proper value.  You can check this by adding another capacitor of the
same type and similar value(try 50% of the other) in parallel.
  If this makes it more
rectangular, then you can add an appropriate value of a capacitor in 
parallel without taking out the other one.  But if it made the screen more
trapezoidal then you'll have to take out the capacitor and replace it
with one of smaller value.  If something else happens entirely, then
the reason is (prbably?) something else.  If it fries your computer, well
... uhh.. :-)      But that shouldn't happen.  I'd risk trying this if
this happened to me.

			- Chung