On 04/02/2013 01:32 AM, Chris Howe wrote:
Hello,
I was running SL6.1 OK but now the display no longer works - On boot
the top half of the display is readable but the bottom half is
rectangles of black and the screen. The mouse won't move into the
lower half of the screen and produces a trail of black behind it. If
I login the menus at the top are accessible but in half the width that
they should be.
I know that the monitor is OK as I use a KVM switch for another
computer - I have also connected the monitor directly to the PC with
no improvement.
Something very similar happened a while back as a result of the
"universal access" screen helper/magnifier thingy misbehaving:
http://scientificlinuxforum.org/index.php?showtopic=2048
The solution there was to turn the accessibility/screen-magnifier
program off (the user hadn't intended to have it running in the first
place).
You mention a KVM switch... if an accessibility program isn't the
problem, try wiring your system up without the KVM switch in the middle
and see if your system can build a workable Xorg config on its own (make
sure you move/remove xorg.conf first). In the past I've had problems
where I toggled the KVM switch at a bad time which made SL (and OS X)
re-probe and get crazy results on multi-screen displays.
Beyond that, this will probably become a graphics driver thread. I would
check the above two things thoroughly before anything else; usually when
drivers or Xorg config is wrong X doesn't start at all, so it makes me
think this is more a screen effect gone wrong or a probe/detection issue
with X.
