Second Display in Dual Display Setup Has Stopped Working

[ed3120]

I have a PC with dual monitors. Both monitors worked fine for a year, but one day the second display stopped working, and the second monitor

It’s an Intel based system with PCI-E ATI HD2600 Video card with dual DVI out. Monitors are both identical Acer 22 inch LCDs.
The issue is that monitor A shows a proper display, but monitor B is blank and goes into power save mode.

If I switch monitor A with monitor B, same result. Hence, both monitors are in working condition.
If I swap DVI cable A with DVI cable B, same result. Hence, both DVI cable are in working condition.
I’ve tried replacing the video card with a new PCI-E card of a different brand. Same result. Hence the video card is not broke.
If I only plug one monitor into the video card’s DVI output A, it’ll work. If I only plug one monitor into the video card’s DVI output B, it’ll work. Hence, both DVI outputs on the video card work, just not at the same time.

Issue occurs the same during POST, as well as in Windows and Ubuntu. It’s not a driver issue. I’ve tried updating the drivers.

I’m not sure what this could be.

 

[shabaa]

There is a component in your vid card that has failed and only 1 of you DVI outputs are functioning. If the card is under warranty get it replaced... otherwise replace the card.

 

[ed3120]

That's what I originally thought, but I replaced the video card with a new one and I have the same issue.

 

[qqq]

this has happened to me several times. each time the dvi monitor had failed to display it had been after a shady install of an unrelated piece of software, or after an improper shutdown. the dual monitor was working and 5 min. later, it was not. each time i was able to successfully get the dvi monitor to work by reinstalling the latest video card driver. all suggestions by people that the cables fail, the monitor fails, the card fails, are just guesses. this seems to be a quirk that happens so infrequently that hardware/ software producers are not compelled to deal with it. my card is an nvidia 6600gt and this solution worked for me 100% of the time.

i also came across this while in search of a solution for my card
http://forums.extremeoverclocking.com/showthread.php?t=320971
this might be what you're looking for

good luck

 

[ed3120]

Yeah, but the issue occurs for me even at boot/POST, which is before any drivers are loaded. It can't be driver related.

 

[qqq]

personally i still suspect the drivers. in my situation i have a vga and a dvi (versus 2 dvi in your situation) and at boot/ post i had experienced the same 2nd monitor showing black. after installing the latest driver, all symptom vaished, even at boot up.

i also found that i had to use the nvidia display properties menu to get my dual monitors to configure properly. (for some reason, unknown to me, windows wouldn't let me do it)
once again, good luck

 

[ed3120]

Yeah, but unless the drivers actually write something to the card (like flashing a rom or something) then the drivers won't matter during POST. The same goes for Ubuntu, which also has the same issue for me.

 

[achalupa]

I have been battling the same situation on an intel dq45cb motherboard, changed monitors, cables, drivers and still the secondary display only works on VGA not dvi. Sometimes it will work on dvi after 20 attempts to activate and extend the display but it is driving me crazy as I have practially elliminated all single points of failure. The only thing left is to buy two expensive DVI monitors (high end). I have already tried 3 motherboards, 2 different sets of matching monitors 5 different DVI cables etc. to resolve this issues. Please help.

 

[achalupa]

I have been battling the same situation on an intel dq45cb motherboard, changed monitors, cables, drivers and still the secondary display only works on VGA not dvi. Sometimes it will work on dvi after 20 attempts to activate and extend the display but it is driving me crazy as I have practially elliminated all single points of failure. The only thing left is to buy two expensive DVI monitors (high end). I have already tried 3 motherboards, 2 different sets of matching monitors 5 different DVI cables etc. to resolve this issues. Please help.

 

[ronkib]

my problem is that my second screen stopped working and suddenly i cant open my nvidia controp panel and the other nvidia panel just vanished, i cant find it anywhere.

Im sorry for this 6 year late post but hopefully someone will answer.

 

[SteeeveTheSteve]

my problem is that my second screen stopped working and suddenly i cant open my nvidia controp panel and the other nvidia panel just vanished, i cant find it anywhere.

Im sorry for this 6 year late post but hopefully someone will answer.

This is probably a bit late for you, but It is probably trying to display on the second monitor that isn't working. Hold the windows key and click the left/right arrow keys several times and it should bring it over to the current window. Setting it to clone or single display may work also.