Monitor problem

I have a strange problem with my new 20" wide screen monitor (LG). Its native resolution is 1680x1050. Sometimes the monitor recognizes the resolution correctly but sometimes it recognizes it as 1280x1024 (WB settings not changed). It might get this wrong if I switch between screens (Amigas screens), when screen saver is used, I have to boot, I watch a video file (with different screen mode) or anything. It might get it correct when I switch between DVI and VGA connector and back (button in monitor) or I use ScreenMode.prefs to change between two different modes (and back).

Is this OS4 driver problem or is this common problem with new monitors or is this just bad luck ? I use VGA connector (obviously). (The problem is same with both Radeon 7000 and 9200.)

Is it possible to change other settings from monitor driver tooltypes and not only vertical (?) sync ? I think Picasso96mode(.prefs) is useless. I couldn't make it to work. (I think it's from 80's, best to use with old CRTs and OCS/ECS/AGA chipsets only.)

@TSK

When your monitor has an on-screen menu, you can check
if it displays the sync polarity. You can specify -hsync
and/or -vsync in the monitor driver tooltypes, some monitors
are too dumb to detect a screenmode change when the syncs
dont change and the frequencies are similar. Eventually
the monitor driver is unable to switch one or both sync
signals, some cant do that because some gfx board features
(hardware sprite etc) would not work otherwise.

When your monitor has an "Auto" button, pressing it may
force resyncing the display.

When your monitor has a manual which lists supported
screenmodes and their sync values, use this table.

When everything fails, your last chance is to give
each screenmode a different frequency. When this doesnt
work too, try a better monitor or delete all non-native
resolutions (due to interpolation they normally look ugly
anyway) which your monitor seems to be unable to distinguish
from the native resolution.

@TetiSoft

Should I put this -hsync in the end of the "MODE" tooltype or should I put it on a new line ? Is it in Hz or kiloHz ?
"MODE=1680x1050@60-hsync=65290" is this correct ? Btw. the monitor is LG L204WT.

@TSK

I would suggest these tooltypes for L204WT:

VSYNCMIN=56
VSYNCMAX=75
HSYNCMIN=30000
HSYNCMAX=83000
MODE=640x480@60
(MODE=640x480@75)
MODE=720x400@70
MODE=800x600@60
(MODE=800x600@75)
MODE=1024x768@60
(MODE=1024x768@75)
MODE=1152x864@75
MODE=1280x1024@60
(MODE=1280x1024@75)
MODE=1680x1050@60

I've commented out () supported modes with the same resolution but different vsyncs.

@Gazelle

I would suggest using the 75hz modes for all moeds except 1680x1050, I do that and have no problems. eg.

VSYNCMIN=56
VSYNCMAX=75
HSYNCMIN=30000
HSYNCMAX=83000
MODE=640x480@75
(MODE=720x400@70)
MODE=800x600@75
MODE=1024x768@75
(MODE=1152x864@75)
MODE=1280x1024@75
MODE=1680x1050@60


The 2 I've commented out are rearely used, so not much point having them listed all the time.

ScreenMode.prefs editor shows me horizontal frequency is 66,13 kHz when manual of my monitor tells I should use 65.29 kHz. Maybe this is a problem ? My monitor selects wrong mode often after reboot. And I can't change a screen mode of Uboot. So if anybody can tell me where to put that "-hsync" tooltype correctly ?!

@TSK

Just append it:

MODE=1680x1050@60-hsync

Btw, it changes only the polarity of the sync signal and not the frequency.

Any of the suggestions didn't help ! Thanks people anyway.

@TSK

Do you still have a Picasso96Settings file in devs? If you do rename it or delete it, even if it's commented out in the monitor tooltypes it will still be found and used which will mess things up if it has the default name.

@TSK

You could also try with -vsync instead of -hsync or both:

MODE=1680x1050@60-vsync
MODE=1680x1050@60-hsync-vsync

Or maybe changing to 59 or 61 Hz will help.

@Gazelle

Quote:
Well I didn't test those two together.

Quote:
I have already tested that but it makes picture quality too bad.

Quote:
I think I have never had such file.

@TSK

Quote:
That didn't help.