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From: brindley@ECE.ORST.EDU (Mike Brindley)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Jittery A3000 Video
Message-ID: <1991Mar28.043102.12173@lynx.CS.ORST.EDU>
Date: 28 Mar 91 04:31:02 GMT
References: <12870002@hpsad.HP.COM> <14760@mcdphx.phx.mcd.mot.com> <20144@cbmvax.commodore.com>
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In article <20144@cbmvax.commodore.com> hood@cbmvax.commodore.com (Scott Hood) writes:
>
>Make sure that you first try the fine-tuning adjustment for the A3000's
>display enhancer as per the user's manual.  Sometimes if the fine-tuning
>is just on the edge of correct operation, you can experience a jittery
>display (horizontal only).
>
I'm having what I believe to be the same problem; I'll try to
describe it in more detail.

When powering up my A3000-25 (stock), random scan lines will be
momentarily shifted horizontally (mainly to the right).  The problem
eventually dies out and only occurs if the machine has been turned 
off for several hours (like over night).  The display enhancer is
probably not the culprit since the same thing happens when powering
up with the display enhancer disabled.  Turning on the monitor up 
to 20 minutes before hand does not seem to make any difference 
(the monitor is a C= 1950).  The problem is so bad, that it was
several weeks before I figured out what the yellow text which 
flashes on the screen (loading kickstart and rebooting system)
says.  This is a most annoying problem and is especially 
embarassing when trying to show off your fancy new computer to
friends and family.

I tried to adjust the display enhancer, but the video test
patterns are all perfectly stable, so I didn't change it.

On a slightly different note, why do the colors change when
I put the workbench into a Superhires mode(1280x200/400)
using preferences?  I'm using the default WB colors (black,
white, gray, and light blue); when I change to Superhires,
the light blue becomes a sea green.

Thanks for any help or suggestions you might have.

--> Mike Brindley
    brindley@ece.orst.edu