Monitor conflict on radeon


I have had the Radeon 5800 for a while, works flawlessly through an HDMI cable. Today, I connected an additional monitor to the card. The monitor that was already connected went black instantly and the second monitor displayed the "check video cable" message. I tested each monitor individually and both work on each dvi and the HDMI output on the graphics card, and they both work. There is no option to extend the desktop. If I reboot with both monitors connected, one will be the second monitor of an extended desktop and the other will have the "check signal cable" message. All I can do in that particular case is to make the display that is working the main display and get the desktop active on it. The other will remain with the "check video cable".

Running Windows 7 Home Premium and I do have the latest drivers and software. My guess...the DVI ports send the same signal and it doesnt split it for two monitors? Maybe there is a way of changing that with the software? Only a guess

Thank you for your attention.

Help me Obi Wan Kenobi, you're my only hope.

Catalyst 11.11

2d driver


Open GL
18 answers Last reply
More about monitor conflict radeon
  1. Are you trying to plug two monitors into the same DVI port using a splitter or are you plugging one in DVI and the other in HDMI?
  2. hmm even the cheapest cards should support 2 monitors, thou some cards if i remember will share dvi and hdmi ports, like if u have card with dvi+hdmi+vga they will not support 3 monitors but rather dvi+hdmi (share) and second monitor or vga
  3. I just asked him since he can do anything wrong, I saw ppl asking why their computer won't boot and they finally found that their computer wasn't plugged in...
  4. ive never tried but seems like this fellow (i could be wrong..) is using hdmi for display 1 and dvi for display 2. I know the cable outputs the same digital signal, but could the hdmi port on the graphics card be governing something like this not to work sharing both?
  5. Normally, if an AMD card have 2 or more Outputs, it should be able to display independently an screen each one of them, maby he didn't enable "Extend Desktop to screen 2" in the "Screen Resolution" controls...
  6. whats exact make and model of your video card?? 58XX should be pretty hi end and support 3 or 4 monitors. Im running 6870 using 2 dvi plus hdmi tv all same time. But it all depends on your video card, you should read manual for it to see what you can connect.
    but it sounds like my kids pc, if i have dvi connected and plug in hdmi cable, they would flash and swap video but newer work both, since it got cheap vid card that share ports
  7. I really didn't knew that A graphic Card could share ports and be so cheap... Even my intergrated HD 4250 doesn't share its HDMI and VGA ports... (Maby because they are not all digital) (VGA is Analog and HDMI is Digital) I seen somewhere that says one card can only have one digital, one analogue and one DisplayPort outputs, never 2 digitals? Maby thats why you cannot plug the two screens in?

    I have a dedicated card with HDMI and DVI but I installed an Adapter on the DVI one that changes it to VGA since one of my screens doesn't support DVI nor HDMI.
    They both work. :bounce:

    Maby you should buy an adapter too since DVI can output in both Analogue and Digital.
  8. my integrated got 1 hdmi and 1 dvi and i can use only one,

    maybe i say it wrong each video card got it purpose the cards that lover in price can have all the ports on back (vga+dvi+hdmi+displayport) but they are there for your convenience and not to be used all together,
    They do no "share" per say, they connected to same video channel and video bios simply selects the one you connect.
    Other more expensive card wore specially designed to support multiple monitors, so every port on back works independent. (my work PC got 4, 24inch monitors on one card for example)

    In most cases you can connect old vga+ 1 other, thou.
    Also video card can simply be defective and that's why it don't work
  9. Yep, I agree with you but if the Card is Defective it will simply not display anything or making only one port working.

    Eg. VGA works but HDMI don't, cannot use HDMI port at all...
  10. exact name and model of the radeon 5800 also the same for motherboard
  11. I've had an HP Slimline s5670t for just over a year, with an HDMI cable and a DVI-to-VGA adapter attached to the ATI Radeon HD 5450 graphics card. The HDMI cable goes to my always-in-standby Vizio HD TV, and the DVI adapter is connected to a VGA cable which in turn is attached to my HP 2310m monitor.

    It's been working fine until yesterday, when the screen went blank. Upon reboot, I would see the HP logo and "starting windows", but that's about it, and nothing beyond.

    I since discovered that if I remove the HDMI cable from the card, the HP monitor works OK. If I plug the HDMI cable into the card, the HP monitor immediately goes blank, but I can see images and get sound on my Vizio TV, as long is it is turned on.

    Is it time to replace the graphics card?
  12. try the new 12.1 driver before and i would check the hdmi cable on another set up
  13. scout_03 said:
    try the new 12.1 driver before and i would check the hdmi cable on another set up

    I updated the driver (by clicking on "Update Drive" in device manager). I didn't note the sub-version, but the version I had was 8.x. Now I have 8.892.1.1000. That's not "the new 12.1 driver". How do I get that?

    The HDMI cable works fine - it sends video and audio to my Vizio TV. The problem is that when I plug it in my computer monitor goes blank.
  14. use this dont forget to uninstall the 11.1 before installing the 12.1
  15. Thanks for the help, but I'm still having the same problem. I actually bought a new graphics card which came with Catalyst Control Center 11.3. It didn't work (had the same issue as before: I could not plug the two cables in at the same time). So I put my old graphics card back in, uninstalled 11.3, and then installed 12.1 from your link. Same problem.

    Any more ideas? Thanks!
  16. i would check carefully the hdmi cable since you try another and did not work cable could be making short on the computer case or is short inside
  17. I solved my problem - and wasted a lot of time doing that! I did try a new HDMI cable, but it had the same result. My son insisted it had to be a software setting, not hardware, and he was right. I normally have the the "Multiple Displays" setting in the "Screen Resolution" applet set to "Duplicate these displays". SOMEHOW, the setting changed to "Show desktop only on 1", which is the Vizio TV connected via HDMI. So when the HDMI was plugged in, the computer display would instantly turn off. My son thinks this setting may have changed as a result of a Windows update, but I don't think we'll ever know.
  18. could be change when you updated the graphic card driver,since it's working now good for you
Ask a new question

Read More

Radeon Monitors Cable Graphics