Barry said:
The motherboard bios has no part in this ... the setup of a plug-in AGP
or PCI Express video card is handled entirely by the bios on the video
card. There is a "conversation" between the video card and the attached
monitor over the DDC (display data channel ... basically, a serial port
that is part of the DVI connection) wherein they exchange information
about what resolutions and refresh rates they each support. When the
display fails to work, it's either because this conversation failed
entirely (the programming of the DDC port and/or the details of the
message exchange was incompatible), or because there was no combination
of resolution / refresh rates / other timing parameters that was common
to both the video card and the monitor.
On most video cards, there is an attempt to conduct this exchange
between the card and the monitor once only, at power up, and if it fails
then (in particular if the monitor is not connected or not powered), the
DVI port isn't initialized at all and subsequent connection won't be
successful without a reboot. But some display cards may reattempt this
process periodcially.
The firmware in the display card (the card's bios) is somewhat space
constrained, and the windows drivers have more space (as much as they
need, really) to support a much wider variety of display modes than the
video bios. Also, the Windows drivers are more "fluid" in that they can
be revised while the display card's bios is frozen unless the
manufacturer wants to make display firmware upgrades available (and
generally, ATI doesn't seem to do this, in fact almost seems to have a
policy against it). Thus, after the card is shipping if it's discovered
that a particular display doesn't work, the video driver may be easily
revised do add whatever support is necessary. The firmware might be
revisable also (if space permits), but getting the revision installed
would require a firmware upgrade, and, again, ATI at least seems to have
a policy against firmware upgrades to their video cards.
It's not just ATI you won't find firmware updates for nVidia cards
either. To me this problem is no big deal. I just keep one VGA LCD on
hand for setting up new systems, just as I do for keyboards and mouse
since not all motherboards will see a USB keyboard or mouse till you
can get into the BIOS so you need the good ole wired units to start
with. My normal use LCD doesn't have a VGA connection, its strickly
DVI, just like my video output on my computer is only DVI but it came
with a VGA adapter to work with older monitors.
[I'm a degreed engineer and have been a product manager for LCD monitor
displays]
Re: "I disconnected the VGA monitor and then plugged in the DVI monitor.
Powered on the DVI monitor and it comes up with blue screen for 5 to 10
seconds then shows the desktop"
That is an unusual/uncommon outcome.
Not necessarily unusual as that is how my system works.
Also don't forget that the motherboard BIOS can play a part in this problem.
