refresh rate on Dell D1025HE

pickarooney

My monitor is flickering like bejesus and I'd like to change the refresh rate, but I'm all afraid of putting in the wrong value and having to pick shards of exploded monitor out of my face. Can anyone tell me for definite what the HorizSync and VertRefresh rates should be for this monitor? I changed the VertRefresh to 60.0-120.0, but it reset itself next time I logged in.

From /etc/X11/XF86Config-4:

Section "Monitor"
Identifier "monitor1"
VendorName "Plug'n Play"
ModelName "Dell D1025HE"
HorizSync 31.0-92.0
VertRefresh 50.0-120.0# Sony Vaio C1(X,XS,VE,VN)?
# 1024x480 @ 85.6 Hz, 48 kHz hsync
ModeLine "1024x480" 65.00 1024 1032 1176 1344 480 488 494 563 -hsync -vsync

# TV fullscreen mode or DVD fullscreen output.
# 768x576 @ 79 Hz, 50 kHz hsync
ModeLine "768x576" 50.00 768 832 846 1000 576 590 595 630

# 768x576 @ 100 Hz, 61.6 kHz hsync
ModeLine "768x576" 63.07 768 800 960 1024 576 578 590 616
EndSection


Is there a way of changing it to permanently default to the correct refresh rate in KDE (Mandrake 9.0) for all users?

niallb

31.5 to 92 kHz
50 to 150 Hz

For more details, take a look at http://www.vtdata.cz/monitory/D1025HE.html

NiallB

This was the first result from Google, by the way... ;-)

Capt'n Midnight

Refresh rate also depends on the resolution - it's a question of how many lines you are drawing per second.

eg 1024lines @ 60Hz ~= 60KHz Horizontal
800lines @ 75Hz = 60KHz

But the specs on the monitor look like they will do
1024 @ 75/76Hz - which should cut down on the "SHIMMER"


PS. you changed the RANGE not the FREQUENCY so my guess is that it still stayed at 60Hz which is in the RANGE 60-120..


Or put it on a windows PC (shimmer free) and press the OSD button - that will tell you what refresh rate it is on ...

pickarooney

Thanks for your answers, but I'm still lost. What lines must I change exactly?
Do I need to add an extra modeline or change the existing one?

edit : I'm running in 1024x768 resolution.

niallb

The lines you want to change are in XF86Config-4

Section "Monitor"
identifier "monitor1"
VendorName "Dell"
ModelName "D1025HE"
HorizSync 31.5-92.0
VertRefresh 50-150

As you're running Mandrake, you can instead go to a console,
and type in XFdrake.

Select "Monitor" and choose "Do"
Scroll down through generic monitors to "Custom"
Type 31.5-92.0 into Horizontal refresh rate
and 50-150 into Vertical refresh rate

That'll get the range right and may just work for you.
Once that's done, you're unlikely to fry your monitor
if you tweak it.

I'd take Cap'n Midnight's OSD suggestion the other way around
as well. If you get shimmer, press the button to see what frequency you're at and then search through the XF86Config-4
file and comment that one out.

One other thing, could you elaborate on your statement:
I changed the VertRefresh to 60.0-120.0, but it reset itself next time I logged on
Did it work OK once, and then reset itself, or did the line just change back?

You could also try booting from a Knoppix disk,
and if it gives a steady display, copy the /etc/X11/XF86Config-4 file to a safe place and use that.
Knoppix just seems to have better detection routines than
anything else at the moment.

To permanently change, once you've found a good frequency,
you can change the line in the config file to read just:
HorizSync 75-76
for example - however this will prevent you using other screen resolutions and shouldn't be necessary.

NiallB

pickarooney

Thanks Niall,

I used XFdrake to enter custom values for my monitor and the flicker has reduced drastically. It might even be gone completely and my eyes are flickering, I'll know after a good night's sleep