Color artifacts around fonts on LCD monitor (via DVI-D cable)

I

IronFelix

Hello folks.

I bought two same-model monitors, Acer AL1715 smd. The one with
manufacture date 2005.1 displays fonts "correctly". The other, with
manufacture date 2005.8 displays fonts with rainbow artifacts around
them. Artifacts appear especially pronounced if ClearType fonts are
used. I've tried switching DVI-D cables and video adapters -- the
problem persists even when standard 15-pin analog cables are used.

I've taken snapshots of each display:

http://69.203.142.43/~vlad/acer1715smd/rainbows_present.JPG

http://69.203.142.43/~vlad/acer1715smd/rainbows_absent.JPG

Is this an correctable defect? Or do I need to alert Acer? Thanks in
advance!
 
R

rjn

IronFelix wrote >
Acer AL1715 smd. ... with manufacture date 2005.8
displays fonts with rainbow artifacts around them.
Click to expand...

The Al1715 is supposedly a native 1280X1024 panel.
What resolution are you driving it at, and at what refresh rate?
What graphics card or chip?
I've tried switching DVI-D cables
Click to expand...

Are you sure the cables are DVD-D (analog pins not
populated), and thus that there's no chance you're
using DVI-A unknowingly?

With no signal, do the internal monitor menus have a
similar problem?

Another thing to try (although almost certainly a dry
hole): do a [PrntScrn] and zoom the the image in an
image editor. This will rule out the font rendering
being messed up in the graphics card frame buffer.
 
I

IronFelix

IronFelix wrote >
Acer AL1715 smd. ... with manufacture date 2005.8
displays fonts with rainbow artifacts around them.
Click to expand...

The Al1715 is supposedly a native 1280X1024 panel.
What resolution are you driving it at, and at what refresh rate?
What graphics card or chip?
I've tried switching DVI-D cables
Click to expand...

Are you sure the cables are DVD-D (analog pins not
populated), and thus that there's no chance you're
using DVI-A unknowingly?

With no signal, do the internal monitor menus have a
similar problem?

Another thing to try (although almost certainly a dry
hole): do a [PrntScrn] and zoom the the image in an
image editor. This will rule out the font rendering
being messed up in the graphics card frame buffer.
Click to expand...

Thanks for replying!

Both monitors are set to their native resolution 1280x1024 @ 60Hz
Yes, these are DVI-D cables, not DVI-I, and the problem is identical
if I use 15-pin VGA cables. The graphics cards I have used are ASUS
V9900 (GeForce FX 5800), and XFX GeForce 6600GT (dual DVI). I've
switched both cables and graphics ports, but to no avail.

Now, the OSD menu seems sharp and without shadows ( the black-on-gray
looks solid and without artifacts ), so I guess it's not the issue
with the SMD panel, but with the monitor electronics. I've emailed
Acer, but no reply for two days now...
 
J

Jens Kilian

Try to turn off subpixel antialiasing for text... (Microsoft calls it
"ClearType", and I have no idea if you can turn it off in Windows.
In Linux, look for something like /etc/fonts/fonts.conf)
 
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