Question Dual Monitor Setup Strange Issue

[ElectronKnight]

So I bought an HDMI minotor some time ago, and wanted to use it along with my old DVI monitor. But I soon noticed that the DVI monitor has some issues when booting up the system.

When booting up, the system uses the DVI monitor to display the BIOS bootup page, and when windows starts up, it uses the HDMI monitor as the main display and shows login interface. But there is a 30-50% chance that the DVI monitor won't light up. Even more strangely, although judging from the mouse and keyboard lights the system bootup is perfectly normal(I can still log into windows by blindly typing in the password), the HDMI monitor gets no signal either when normally it would display windows login interface.

When I was troubleshooting, I tried to connect the DVI monitor to the motherboards DVI port(but then the graphics card won't work along with the intergrated GPU due to compatibiliy), it worked fine and can light up 100% time. When I booted with the HDMI monitor only and hot plug in the DVI monitor, it also worked fine every time. That means the cables and ports are good right?

And as I tried more times, there are occationally situations where the system won't boot at all(doesn't use drive), or the DVI monitor will light up but only displays a black screen. What is going on? This really bothers me and I fear that it could be caused by faultly graphics card or motherboard.

Can anyone help? Any enlightenment would be appreciated.

 

[Obakasama]

To verify whether the graphics card and the displays are working, connect only one display at a time and boot up to see what happens. Though you've pretty much did it already.

The BIOS on one screen and Windows log-in on another is likely to do with the graphics card cycling through the display outputs; whichever has the 'highest priority' is where the BIOS screen will be displayed. Once Windows loads, it will then revert to the chosen main display. This is what KFA2 aka Galax (manufacturer of my graphics card) informed me, and it doesn't seem like the order can be changed (at least they never supplied a method to do so in my case).

For example, I have two monitors. My main monitor (M1) uses Displayport, and my secondary monitor (M2) uses DVI. BIOS always displays on M2, and Windows log-in on M1.