LCD on VGA flickering

[Poutnik]

Recently I have bought fresh new
PHILIPS S-IPS LCD panel 240PW9 1920x1200 60 Hz.

I have attached it to Intel GMA 3100 integrated graphics ( G33 chipset)
through VGA/D-SUB(?) connector.

I have realized the LCD is displaying over otherwise good image
very broad bands, with pulsing brighness, verz unpleasant to eyes.
Thez were quickly moving up with frequency of several hertz.

Similar result was at all resolutions and refresh rates,
even 1024x768 or 800x600 60/75 Hz.

But, when I have attached Lenovo Thinkpad notebook,
with VGA / D-SUB connector too, the image was OK.

The GMA 3100 graphics was previously attached
to 15in old CRT monitor 1024x768 75 Hz.
Screen was small, brightness aged, but otherwise OK and stable.

What could be the reason of such instability ?
If the cause is GMA3100, why CRT picture is OK ?
If the cause is monitor, why it is OK with Notebook ?

Note that at this time I have bought
GAINWARD card based on NVidia GTS 250 with DVI-I connector,
so there is no issue anymore.

But I am curious what could be the reason.

 

[smlunatick]

Recently I have bought fresh new
PHILIPS S-IPS LCD panel 240PW9 1920x1200 60 Hz.

I have attached it to Intel GMA 3100 integrated graphics ( G33 chipset)
through VGA/D-SUB(?) connector.

I have realized the LCD is displaying over otherwise good image
very broad bands, with pulsing brighness, verz unpleasant to eyes.
Thez were quickly moving up with frequency of several hertz.

Similar result was at all resolutions and refresh rates,
even 1024x768 or 800x600 60/75 Hz.

But, when I have attached Lenovo Thinkpad notebook,
with VGA / D-SUB connector too, the image was OK.

The GMA 3100 graphics was previously attached
to 15in old CRT monitor 1024x768 75 Hz.
Screen was small, brightness aged, but otherwise OK and stable.

What could be the reason of such instability ?
If the cause is GMA3100, why CRT picture is OK ?
If the cause is monitor, why it is OK with Notebook ?

Note that at this time  I have bought
GAINWARD card based on NVidia GTS 250 with DVI-I connector,
so there is no issue anymore.

But I am curious what could be the reason.

A flickering LCD screen can be mainly caused bu old or poorly designed
drivers.

Always update video card drivers and also check for a monitor driver.