bill@mwca.UUCP (Bill Sheppard) (11/06/90)
My mono display has been exhibiting weirdness lately - any ideas would be
welcome:
The display starts flickering where vertical lines will be drawn approximately
every eight characters, heavier at the top of the screen, lighter towards the
bottom. It seems to be worst when I first turn on the monitor, although today
it hasn't gone away. Fainter vertical lines are drawn between the heavier ones,
and at times all the white areas of the display will become black, but there is
a fuzzy white shadow near where the text would be.
My assumption is that this is a monitor problem, not an ST problem, for two
reasons. First, using the ST with a color monitor works fine. Second, bouncing
around the ST has no effect. Also, since the lines are fainter towards the
bottom this seems like an analog problem, not a video memory problem.
Do these symptoms sound familiar to anyone? Any suggestions what to replace in
the monitor, or should I take it in, or just scrap it?
--
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# Bill Sheppard -- bills@microware.com -- {uunet,sun}!mcrware!mwca!bill #
# Microware Systems Corporation --- OS-9: Seven generations beyond __/_!! #
#######Opinions expressed are my own, though you'd be wise to adopt them!#######bill@mwca.UUCP (Bill Sheppard) (11/13/90)
In article <1737@mwca.UUCP> bill@mwca.UUCP (Bill Sheppard) writes: >My mono display has been exhibiting weirdness lately - any ideas would be >welcome: > >The display starts flickering where vertical lines will be drawn approximately >every eight characters, heavier at the top of the screen, lighter towards the >bottom... and other horrible symptoms... >My assumption is that this is a monitor problem, not an ST problem... After receiving mail from several people (thanks!) suggesting both monitor and ST problems, my further experimentation has indicated a _monitor_ problem - I've made a cable for use with a Sony 1302 multisync in mono mode and there is no indication of trouble. One suggestion was that the circuitry in the monitor which differentiates between low and high (light and dark) may be getting flaky - this sounds reasonable based on what I see. It is interesting that vertical lines were seen on exact character boundaries, though perhaps there is a slight variation in signal level at these points which is enough to affect the monitor. At any rate, I'll be taking it in for repair in a few days. As a side note, the Sony works reasonably well as a mono monitor, though characters aren't quite as clear as on the SM124 (which makes sense considering there are three beams for each pixel, as opposed to one on the mono monitor). I could wire up only R, G, or B, but none of those three color choices sounds too appealing. There is also some slight bowing of the screen near the top... -- ################################################################################ # Bill Sheppard -- bills@microware.com -- {uunet,sun}!mcrware!mwca!bill # # Microware Systems Corporation --- OS-9: Seven generations beyond __/_!! # #######Opinions expressed are my own, though you'd be wise to adopt them!#######