Dual Display Issues - NO SIGNAL

Discussion in 'Mac Pro' started by Gh0stKiller, Aug 25, 2010.

  1. Gh0stKiller macrumors member

    Joined:
    Aug 10, 2010
    #1
    Hey everyone,

    Long-time reader here, first-time poster. This forum helped a lot with my recent decision to upgrade to the hexacore Mac Pro, but I'm already having a little bit of trouble with it. Sorry to take advantage of you guys like this, but I figured you were the best place to turn before I have to start calling Apple Support.

    So, I just set up my hexacore Mac Pro with stock ram and the ATi 5870. To go along with it, I purchased two Dell u2311h monitors from Dell so that I could finally have dual displays. I then purchased two 6' minidisplayport to displayport cables from Monoprice. Also went with the Apple wireless keyboard and Magic Mouse.

    Upon initial start-up, everything worked fine. The monitors needed to be calibrated, but dual display mode worked perfectly without any extra steps. I had some fun messing around for a little bit and then decided to take a break. I put the computer to sleep.

    I came back 15 minutes later (couldn't stay away for long), and clicked the mouse to wake the computer back up. I heard the tower humming, but the monitors stayed black. I tapped the keyboard. Still black. Assuming it was some issue I wasn't prepared for with the wireless peripherals, I futzed around with them for a while and had no luck. Still not image on the monitors. I turned the monitors off and then back on only to get an error message explaining that the monitor was in Power Save mode. Some further exploration revealed that the monitors were allegedly getting NO SIGNAL from the computer.

    Restarting didn't help any. The only thing that has "worked" is shutting down the computer and connecting a single monitor through the DVI-D cable that came with it. Both monitors work, but obviously not together. In doing some research, I've found some threads on different sites about people having similar dual display issues attributed to faulty graphics cards. I certainly hope this isn't the case, but aside from two faulty cables (and I've never had any trouble with Monoprice cables in the past), I'm at a loss for what the problem might be. It seems odd that dual displays would work briefly only to fail after going to sleep for 15 minutes.

    Sorry if this is the dumbest question ever. Is there something stupid that I'm doing wrong? Anyone have any insight?

    Any guidance you guys can provide would be greatly appreciated. Thanks in advance!
     
  2. Vylen macrumors 65816

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    Jun 3, 2010
    Location:
    Sydney, Australia
    #2
    I have a similar issue... 3 monitors, Samsung by DVI and 2x U2311H by MDP. On the rare occasion on cold-booting no displays get driven if all are plugged in, solved by plugging in only the Samsung and then plugging in the Dell monitors.

    [EDIT]Oh, and my main monitor is one of the Dell's... so it has to power that one up first and give it a signal on boot[/EDIT]

    It's "nice" to see someone here is having similar problems. Can you link me to the other threads you found? I'd like to read them for myself.
     
  3. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #3
    Here's a couple of threads where users have more or less concluded that their "no signal" issues were due to a faulty graphics card. Obviously, these don't pertain specifically to the 2010 Mac Pros or the Dell monitors, but as the issues are so similar, I figured the diagnosis is at least worth looking into.

    http://discussions.info.apple.com/message.jspa?messageID=7938254

    http://forums.macworld.com/index.ph...pu-no-signal-after-display-resolution-change/

    That's interesting that you're also having problems specifically with the U2311h. I wonder how much that has to do with it.

    New info: Like I said earlier, my monitor wakes up from sleep mode normally as long as its connected through DVI-D. I just tried connecting the minidisplayport to displayport cable while I was running through DVI-D and then switching the input. Both monitors now work fine in dual display mode. Obviously, this means that it is not an issue with the cables.
     
  4. Vylen macrumors 65816

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    Jun 3, 2010
    Location:
    Sydney, Australia
    #4
    I think i'll wait to see if other people have problems either with dell or non-dell monitors... I haven't put this machine to sleep so I can't say if i do have exactly the same problem.

    It's only happened twice to me... if it happens again, maybe ill try reseating the card/power... I dunno, heh.
     
  5. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #5
    I'm going to try updating the graphics card drivers tonight and see if that helps any.
     
  6. jenzjen macrumors 68000

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    Aug 20, 2010
    #6
    No problems here; I have a hex/5870 driving 3 Dell U2410s (2 via MDP to DP cable, 1 DVI-D).
     
  7. Vylen macrumors 65816

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    Jun 3, 2010
    Location:
    Sydney, Australia
    #7
    Which one is your "main" monitor? i.e. the monitor that shows the grey bootup screen. If it isn't already, try set it to, say, the right-most MDP and do a cold boot?
     
  8. eponym macrumors 6502

    Joined:
    Jul 2, 2010
    #8
    I also have u2311h running via a mini DP to full DP cable from Monoprice. But it's the 5770 (and only 1 monitor at the moment). Haven't had any issues.

    It's hard to say what might be the cause. Dell gear can be finicky. Could be bad port on one display screwing up signals. Could be bad cables. Could be a faulty card. Bad firmware....etc

    Just some clarification: do you also turn off your displays after you sleep the Mac?
     
  9. Mr. Anderson Moderator emeritus

    Mr. Anderson

    Joined:
    Nov 1, 2001
    Location:
    VA
    #9

    Where do you find the drivers for the cards - I'm having a different issue with my new MacPro, but I'm thinking updating/reinstalling the drivers might fix things.

    D
     
  10. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #10
    No, they automatically went into power save mode.
     
  11. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #11
    I actually haven't looked yet. At work right now. I'll have to try and tackle it when I get home tonight.
     
  12. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #12
    Can I ask where your MDP to DP cables came from?
     
  13. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #13
    I've pretty much ruled out the monitors and/or the cables as the culprit. They both seem to work fine independently. It also would be very odd that I just happened to receive two monitors with a bad displayport. I could be wrong, however.

    For lack of a more technically precise way to put it, it seems to me like the minidisplayports on the computer are not "waking up" from sleep mode.
     
  14. jenzjen macrumors 68000

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    Aug 20, 2010
  15. jenzjen macrumors 68000

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    Aug 20, 2010
    #15
    When I was setting it up, I had both MDP ports set as my "main" LCD at different times, so I did boot it cold off both MDP ports but have always had all 3 monitors connected.
     
  16. Gh0stKiller thread starter macrumors member

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    #16
  17. Gh0stKiller thread starter macrumors member

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    #17
  18. wally21 macrumors member

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    Mar 7, 2009
    #18
    So I've hooked up my two u2711's to my 12-core 2.93Ghz system with a 5870 graphics card.

    I used the displayport -> mini-displayport cables from Circuit Assembly.

    These cables seemed to be of a better quality than the monoprice ones.

    I haven't had any issues yet. I'll keep you posted if I do.
     
  19. Framedvision macrumors newbie

    Joined:
    Aug 28, 2010
    #19
    Problems

    So I have two U2711 monitors and they are both plugged into the mini display ports... When I boot, I get nothing. It's interesting to not that if you screen share your macpro, (i screen share with iteleport on my ipad) you can see that osx has booted normally but if you go to system profiler and look at the graphics section, it will say No Information Available. The only way I am able to get the monitors to initialize is to turn of the computer completely, and then plug in ONLY the Dual link DVI of one monitor, wait for the computer to boot up fully, then unplug the dual link and plug in the two display ports to mini display ports. Then it work fine unless I put the computer to sleep. I can replicate this every time and it's alway the same. It's worth noting that I am writing this because I just got home from replacing the graphics card with a brand new one from the apple store, they had to order it, SAME problem. So It's Definitely an issue with either, 5870, the dell U2711's, or the cables from monoprice. I am going to try and order the cables that wally21 suggested from Circuit assembly.

    I REALLY hope this works.

    Does anybody have any other insight into this problem?
     
  20. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #20
    Damn, that really bums me out. I am taking mine into the Apple Store this evening so they can take a look at the graphics card.

    Over the phone, they told me to try using two of the Apple minidisplayport to Single-link DVI-D adapters. They did not work. Got no signal whatsoever on the second monitor. For me, this pretty much indicated that the 5870 must be the culprit...but if they replaced yours and it still has the same problem, now I'm not so sure. Maybe it's possible you just got two bad graphics cards?

    I'm really sick of playing this game. Hopefully, I'll have better luck than you did with the Genius bar(no offense).
     
  21. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #21
    BTW, did you see this?

    http://en.community.dell.com/support....aspx#19722024
     
  22. Framedvision macrumors newbie

    Joined:
    Aug 28, 2010
    #22
    Well

    Ghostkiller, I really hope you do have better luck. Just a heads up, they will have to order the card card since they do not have stock of them yet. I truly hope you have better luck because then at least we know there is a solution. Meanwhile, I ordered the circuit assembly cables to see if that helps. Just know your not alone now in the quest for a solution... And I will not rest to I get a solution. Good luck guys!

    By the way, the link above didn't work.
     
  23. Gh0stKiller thread starter macrumors member

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    Aug 10, 2010
    #23
    Thanks for the well wishes, my man.

    I did in fact have better luck. I owe my computer an apology. There is nothing wrong with the graphics card. I lugged the whole thing in to the Genius Bar on Friday and the very friendly guy who helped me had two monitors running fine in about a minute. Putting them to sleep, waking them back, everything worked great, it just took a little bit longer for the secondary monitor to come around.

    I now have both monitors working through Apple's minidisplayport to DVI-D adaptors.

    This means it's either the Monoprice cables or the monitors themselves. He didn't have a way to test the cables since they didn't have any displayport monitors available. Obviously, I didn't bring the monitors with me.

    My suspicion would be that maybe there was nothing wrong with your orignal graphics card either. Maybe the Genius that helped you didn't test it fully before he made the diagnosis, although obviously I wasn't there.

    The articled I attempted to link you to was a thread on Dell support forums where users were reporting basically the exact same problem you and I were having, specifically with the Dell U2711. They had eventually concluded that the monitors drop the displayport connection when they go into power save mode, but then are unable to reestablish it without a restart.

    I'm not yet sure if it's worth it to me to return the monitors due to faulty displayports. I'm definitely thinking it over.

    Let me know if those new cables work any better. It would be the easiest solution, that's for sure.
     
  24. b.lam macrumors newbie

    Joined:
    Sep 5, 2010
    #24
    Hi everybody,

    it seems that the displayport issue also occurs when using only one display.

    I have a NEC MultiSync EA231WMi and the 2010 Mac Pro with the 5870. My odysee with this issue started with WoW:

    The display is delivered with a DVI cable, so I first used this one. But when starting WoW in fullscreen/maxed window mode, the display resolution was set from 1080p to 1080i. I could set the resolution back to 1080p via the system settings, but it was annoying. After doing some research I found some information that someone had the same issue with a 2008 Mac Pro/Radeon 4870 when starting City of Heroes and he solved it by using a MiniDisplayPort to DisplayPort cable. Therefore I bought such a cable from DeLock via Amazon.
    When I got it, I first tried the MDP right next to the DVI but I got no signal. Then I tried the other one and it worked, but it was very sensitive to any motion on the Mac Pro side. A slightest touch and the signal disappeared (why the heck are they using MDP at all? There's enough space for 2 DP and 1 DVI plug and the MDP seems very fragile to me). This worked for about 1.5 weeks (and btw, it did not solve the resolution issue with WoW :-/).

    A few minutes ago, I woke my Mac from sleep and got no signal on the DisplayPort. I tried everything from shutting down and unplugging the display for 30 seconds from power supply, trying also the other MDP interface on the graphics card. No luck. It seems as if the DisplayPorts don't work any more. DVI still works.
     
  25. Framedvision macrumors newbie

    Joined:
    Aug 28, 2010
    #25
    I feel bad

    Because I too owe my computer an apology. The first graphics card I'm sure as fine because the replacement does the same thing. I actually took one of my u2711's in the first time. Here is the funny part, it works flawlessly via Mac pro 4870 mdp to dp but not with the 5870. So it's a combination of something of 5870 AND Dell. But let me get this straight, you purchased one mdp to d-link dvi and the other monitor is just plugged into the dvi correct? And that works fine?

    By the way, new circuit assembly cables will be in tomorrow, will let u know if they work.
     

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