View Full Version : 6800GT Dual Monitor - LCD blank in DOS mode

08-30-05, 09:01 AM
Anyone have any idea what could be happening here?

Asus 9999GT (6800GT 256Meg AGP)
MB Asus K8N-E Deluxe BIOS 1006

When I have my LCD connected via DVI which I use as my primary monitor, and my CRT connected to the VGA connector, I am unable to get any images to display on the LCD in DOS mode (fullscreen of course).

This means that when I reboot, my LCD is blank until I get to the Windows logon screen. Also meaning accessing the BIOS is a bit tricky. Also note that the graphical ASUS logo on boot does not display at all on either monitor, and the BIOS will not display ont he secondary...all I get is a flashing cursor (and I assume the BIOS is being displayed on the inactive LCD).....the CRT monitor displays all the rest of the screens up until the windows log-on, but as I said before....no LCD before then.

If either of the monitors is unplugged and I reboot, I have no trouble accessing the BIOS, or any DOS mode screens. So this only happens with 2 monitors plugged in.

I have had no trouble with this arrangement with a Radeon9800XT in the past so I am loathe to blame any hardware but the graphics card.

Are there any non-volatile settings in the card that could have been screwed up perhaps?

09-07-05, 10:32 PM

I have been on holidays for three days, and my PC has been OFF for that period. It normally doesn't get a rest.

The graphics card is back to working order and goes into "clone" mode in DOS resolutions now.

I have already tried removing the card for a few minutes at a time but that didn't fix it. Note that I also left the PC plugged into power over that period, so the motherboard was pulling a small current over that time (dunno if any gets to the graphics card, as it would only be for "Wake up" events.

Anyway.......turned it off for 3 days, all is good.

09-07-05, 11:26 PM
yes same has happened to me. i found that clearing CMOS and turning off the power (for 5 minutes or more) will fix the problem. i have no idea what causes it, but the monitor comes on as soon as the windows driver loads. its weird.

maybe changing the bios option for display port from PCI to PCIe would help, but i havent tried that yet

09-16-05, 11:07 PM
I don't think the MB BIOS has much to do with it. That 5 minute power-off must reset some semi-volatile settings in the graphics card and put it back to rights.

I have always had my MB settings set to AGP (being the AGP model of course), but it is a non-issue since I don't have a PCI card installed at the moment. The only use for that would be to recover from a bad flash. If youre prone to flashing BIOS often, leaving it to PCIe would be best. (or better, setting it just before you flash).

Otherwise, if you need an absolute ton of heads for flight sims or whatever, leaving the presumably faster PCIe card as primary is probably the go.