On Tue, 6 Sep 2005, Bob Chiodini wrote:
On Tue, 2005-09-06 at 20:58 -0400, Matthew Saltzman wrote:
(1)
Video card: NVIDIA GeForce 2 MX (generic)
Monitor: Samsung SyncMaster 930B (flat panel)
Driver: nvidia (the commercial one), but it happens as well with nv.
Resolution: 1280x1024, 32-bit color or 16-bit color
Sypmtom: Monitor flickers as if it's synching at very low rate.
The monitor reports that it is syching at 75Hz, but I still see flicker.
(2)
Video card: ATI Radeon Mobility 7500 in an IBM Thinkpad T41.
Driver: radeon
Kernel: kernel-2.6.12-1.1398_FC4
Kernel option: video=radeonfb
X: xorg-x11-6.8.2-37.FC4.45
Symptom: When I use the VGA-out jack to connect to an overhead projector
or external monitor, the projector image ripples slowly, as though (very
narrow) waves are passing over it.
In FC3, this behavior varied with the kernel version. In FC4, I need this
kernel in order to get proper ACPI behavior, so I haven't tested much. In
WinXP, the display is rock-solid.
For (1), could this be the monitor? It's brand new. I also recently
installed a TV tuner card, but that doesn't seem to be too likely a
culprit. I didn't *think* I was seeing the flicker before that, but it's
my wife's monitor, so I didn't spend much time with it. My machine (CRT,
no TV tuner) is rock solid.
If it's not the monitor, what should I be looking for to further isolate
the problem?
For (2), I'm pretty convinced it's a bug, but I' not sure what component
to report it against. In FC3, it varied with kernel version, with
whatever XFree/xorg was installed. So I'm sort-of thinking kernel.
Thanks for any suggestions.
--
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs
Matthew,
1) Try lowering the vertical refresh to 60 Hz. I'm not familiar with
that display, but both the Dell and the Viewsonic recommend 60 Hz.
Is this an xorg setting? The refresh rates are what is selected when I
run system-config-display. There doesn't seem to be a way to set this in
the monitor menu. How would I set it?
2) Are the vertical and horizontal rates the same between Windows and
FC4?
Are they the same laptop?
If you answered yes to both then I'm stumped.
Yes, it's the same laptop running WinXP and FC4 and FC3 with several
different kernels.
But...
If the refresh rates are not same then adjust FC4 to the same as
Windows.
The problem sounds like a bad/low quality cable. Cable performance will
get worse as the refresh rates go up. Could also be a grounding problem
inducing hum in the video signal.
If Windows and FC4 are not running on the same laptop then I would
suspect a hardware problem with the FC4 laptop.
That's two suggestions for the cable. I will try some others, but it's
not clear why the same projector and same cable and same hardware behaves
differently when I use different software.
Thanks for the suggestions.
Bob...
--
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs
