RayLopez99 said:
I bought a cheap new LCD 15" monitor and find that my mid-priced Radeon graphics card (ATI Radeon HD 4600 series) only suggests (and will not allow me to change) a screen resolution of 1024x768, despite the fact the Radeon card recognizes the monitor can in theory can support 1920x1080 at 72 Hz.
Playing around with the ATI Catalyst Control center program, including the Display Detect Option ('use manual detect only' as per this thread:
http://superuser.com/questions/96683/how-do-i-fix-monitor-detection-in-windows-7) and clicking on and off the "EDID" Extended Display Identification Device checkbox, was of no use, as the OS will not allow me to pick a higher resolution than 1024x768.
I suspect it's a feature rather than the bug it really seems to be, to prevent people from picking the wrong resolution. It's not a bad idea I suppose, and 1024x768 is good for only a small 15" screen.
RL
Use Moninfo. Look for a "real-time" entry in the upper left,
click it, and see if there is actually data present. Chances
are, something is wrong with EDID serial connections, or
the chip wasn't programmed, or it got overwritten.
Moninfo is free.
http://www.entechtaiwan.com/util/moninfo.shtm
*******
On display devices lacking EDID (projectors), you can
add an "EDID box" in line with the video connection,
to present a "fake EDID" to the computer. So that
can be used to compensate for poorly implemented
equipment.
http://www.gefen.com/kvm/ext-hdmi-edidp.jsp?prod_id=8005
http://www.gefen.com/kvm/dproduct.jsp?prod_id=1378
Cheap ones available.
http://www.amazon.com/ConnectPRO-VGA-EDID-KITU-Ghost-Emulator-Eco-kit/dp/B0032F9D0S
As an example, my old Sony Trinitron, was connected
via five coax cables (RGBHV). Meaning, there was
no chance of EDID or anything else. That box, were
it alive today, would be a candidate for an EDID
faker. The monitor was multisync, and originally
ran at 1280x1024 and later in life 1152x864. And
if I faked the EDID, it would have been relatively
simple to set up on a modern system. On the Macintosh
that was connected to, there was yet another kind of
dongle sending fake resolution info (programmed via
DIP switches). So sending fake res info is a common
theme on computers.
*******
On Windows 8, the resolution just happens to "stick"
at 1024x768 - that is, if there is no video driver available.
I had that happen on the computer here, that has a FX5200
with no video driver. You can't change the resolution
on that. And the Preview version of Windows 8, is the only
Win8 the box will ever see.
*******
And yes, the reasoning about resolution selection,
has to do with the history of monitor damage from
running settings which are too high. Just about
any display device you buy now, is protected against
that, and there is hardware present to detect
"out of bounds" conditions. The OSD then displays
the fact you've attempted to run the monitor at
too high a setting. But on older monitors, having
an EDID, or not detecting an EDID, caused the video
driver to take it easy on the monitor.
Paul
