Did you run a Dell Diagnostic test on the machine? Maybe there is
something wrong with the video subsystem on the motherboard. Reset the
BIOS to its default values, if you don't see an option to do that in the
BIOS just pull the power cord on the machine and remove the motherboard
battery, it may take a bit of time for the cmos to drain and revert to
default values, keep the battery out for about 1/2 hour then reinstall
it and see if things have changed. The type of problem you describe can
happen if the monitor is set to an out of range resolution or if the
refresh rate is set to one that the monitor doesn't support. You could
look into that, but being that you tried a different video card and that
you reinstalled the video drivers it is probably only a remote
possibility, but you can check it out anyway.

John

Wallace wrote:

Could anyone suggest what's wrong with my 1 year, 1 day old desktop, other
than out-of-warranty-syndrome?

It refuses to boot up - in fact it gets as far as the black screen just
before it goes blue with the words "welcome" in the boot-up sequence and
just dies- the monitor even powers down! If I disable the video card then I
can boot up O.K.

I've tried everything I can think of, like reinstalling the video driver
plus updated versions of the driver. I've also bought a new video card,
uninstalled the driver and reinstalling them (clean install)without success
plus restored the system to earlier system points. I even have XP reinstall
discs from Dell, but these don't reinstall XP for some strange reason.

User forums suggested the BIOS settings, though I can't see anything wrong
here- the BIOS is set up to use the PCI-X card I have.

I've also done at disk check which hasn't thrown up anything!

I am near to trying out Plan B, which primarily involves throwing the
computer out the window!