MP 5,1 with 5870 – 30” ACD flickering

Discussion in 'Mac Pro' started by kunia, Jan 3, 2012.

  1. kunia macrumors regular

    Oct 30, 2010
    I’ve been having some unusual flickering on my 30” ACD and I need some advice.

    But first, a bit of a back story.

    My 30” ACD was always a bit wonky. I was flickering since I can remember. It was more “intense” with my old MP 1,1 with 8800 GT. It used to go all out into some sort of static on some days, but a simple monitor sleep cycle would reset it. Since I got my MP 5,1 the 30” ACD flickered much less, and it never went into full out static mode. Again, a simple monitor sleep cycle would solve the issue. At one point I got the power brick replaced, thinking it was at fault – new one helped, but didn’t solve flickering completely.

    Few days ago the monitor stared to exhibit some unusual flickering and blue pixels while the video card was under load (in windows 7, playing a game). My current monitor setup is as follows: 30” pulled into 5870 through DVI, 23” ACD plugged into GT120 (slot 2) through DVI.

    Frist time I saw this was few hours into gaming. The whole display showed a bunch of blue pixels and after a while it started to flicker. I’ve quit the game and booted into Lion, but the same stuff kept on showing, even during gray screen boot. After the initial weird flicker + blue pixels I turned off the computer and went away for 4 days and got back into testing yesterday.

    I’ve booted the system into windows yesterday when I got back (wanted to see the temperatures + fan seep of the 5870). The temps where in mid 30C while the video card was idle – fan seep at 20%. After few minutes in Windows, blue pixels started to appear (it didn’t flicker), but they went away after about 30seconds (power cycling the display didn’t help). I’ve started the game and again few minutes into it blue pixels appeared followed by intensive flickering. So I’ve disconnected the 23” and 30” ACD, plugged in the 23” into 5870 (DVI) – 23” didn’t flickered; plugged in the 30” into GT120 (DVI) – it flickered + blue pixels (23” was disconnected) ; plugged into both 23” into 5870 and 30” into GT120, 30” still flickered. While all the crap was going on the 5870 was at load with temp of around 75C and fan speed of 27-30%.

    While I was screwing around with the entire monitor plugging the flickering + blue pixels magically went away with my original configuration (30 into 5870, 23 into gt120). So I’ve started to play a game to see what happens. Well, nothing really happed for about 3 hours – 5870 was in mid-70’s Celsius, the fan speed was between 27-30%. During that time I had a window open so the room was rather cool. At one point, I’ve closed the window and within 20 minutes or so the monitor started to show a bit of flickering, and then went into full-on flickering with those damn blue pixels. 5870 was at about 78C. For the hell of it, I’ve opened the window again just to see what happens. Within 5 minutes the video card temperature dropped to high 60’s, flickering stopped and the blue pixels went away.

    I all honestly I don’t know what to make of this crap. Initially I though the video card was simply overheating but since the monitor was flickering on the GT120 and while 5870 was idle I don’t think that’s the case. I’m thinking that the 30” is screwed up - either it’s overheating or the build-in DVI cable’s trash.

    Few weeks ago I got a 900 watt UPS – with MP, 30 and 23 plugged in it draws at around 450 watts while playing, and I’ve only seen it spike to about 550 when waking from sleep, but again I don’t think it contributes to my monitor issues.

    Any ideas? Any further tests I can do to make sure if it’s the monitor not the video card, or heaven forbid my mac? I’ll be calling Apple Care, but I rather give them a call knowing a bit more.

    I’d appreciate any help.

    side note: at one point, before I got the gt120, the 23” was plugged into 5870 through single link MDP/DVI. The 30” was still flickering, 23” never did + I’ve changed the power bricks when the 30” was going nuts on me yesterday and it still was doing the same with another brick.
  2. kunia thread starter macrumors regular

    Oct 30, 2010

    Looks like video card is not a fault. Yesterday, when the 30" started to display blue pixels & flickering, I plugged it into the GT120 and it was doing the same. I had a PC running next to my mac and when I plugged in the monitor into it the display (at 2560x 1600)was clean. That rules out the monitor (I think).

    Once back in the mac, I was testing the LCD in windows under load (game). Under load (gpu at 75C with about 27% fan speed) it was pretty much blue pixel through few hours of gaming with an occasional flicker. When I booted into lion, the problem was amplified! more blue pixels, tons of flickering and an occasional "static" throughout the display. Btw, Windows seems to be the best and fastest way to trigger it.

    I've spend a few hours with apple care yesterday trying to nail down the problem before I bring my mac to a store. We did the usual regular hardware test which passed, extender hardware test which passed as well, and the smc & pram/vram zap. Nothing really helped.

    I'm clueless. What I can say for sure is that while running the 30" on either video card, the DVI connections are being corrupted as if the dual-link DVI cable connected is not compatible with the system. I am curios thou, what would happen if I were to plug in one of those new 27" apple LED's into 5870's MDP at maximum resolution.

    Anyone with any ideas, suggestions?
    I really don't want to part with the mac since there's a chance I'll come back saying that there's nothing wrong with it (i highly doubt apple will be testing the mac on an outdated 30" acd)

  3. wonderspark macrumors 68040


    Feb 4, 2010
    So this is all happening on Lion? I have a 30" ACD and a Dell hooked to my 5870 (no other GPU in my Mac Pro) and have never seen any problems whatsoever, but I've been on Snow Leopard since day one. For a while, I was using an nVidia GTX285, and it sometimes had glitches and went to snow, which would be fixed by cycling the power off and back on, but that's it.

    Can / have you tried going back to 10.6? I'm currently on 10.6.8 for what that's worth.
  4. kunia thread starter macrumors regular

    Oct 30, 2010
    It's happening in Lion & Windows 7 - haven't tried snow yet (I do have a boot portion with snow so I'll try today). But I don't think it's a software problem. Once the blue pixels start to dance all over the display they even show up during restart, during the gray screen boot sequence.
  5. kunia thread starter macrumors regular

    Oct 30, 2010
    Update 2:

    After further talks with the apple technician, we've decided to take the mac (in it's original configuration) and the 30" to a local apple store. Few hours later with the MP - stripped of HDs, GT120, SSD, PCI usb/firewire controller & OWC ram - and 30" ACD on the floor I started to install Lion off a USB on a new Western Digital hard drive (identical to the one that shipped with the mac).

    Installation went smooth. No flickering, no blue pixels, no glitches. But once I opened safari, with it's short welcome movie, the monitor flickered. Over the next hour or so I got an occasional flicker, but nothing extreme.

    A buddy of mine came over and I wanted to show him the problems. I couldn't get it to go all out nuts on me with clean copy of Lion. So I've decided to plug in my snow/windows hard disk. During all this time, the display was slightly tilted up.

    When I was screwing around with the hard disk I titled the display down. I've booted the computer, and there comes the flickering, blue pixels, static. The I tilted the display all the way up and guess what - flickering + all the other crap was GONE!

    So when the display is fully titled up there's no flickering, blue pixels, static. When it's vertical, there's a an occasional flicker. When it's fully down, it all goes nuts - thrown in a left / right turn to it while in down position and the flickering gets ever more interesting.

    But here's the kicker - when the monitor's in it's down position with all the **** happening on the display while connected to the mac, re-plug the monitor into the PC (at same resolution) and all the crap is gone. Up, vertical, down, turn of flickering, no blue pixels, no static. I actually managed to get the monitor to make a tiny flicker while connected to the PC but I was pretty much shaking the monitor. I couldn't make it to show static, blue pixels or full out flickers.

    All I gotta say to this WTF!? Obviously the monitor's screw up since I technically can get it to flicker on the PC, but nothing remotely close to what I get on the mac. And why the hell the monitor works flawlessly while tilted up. It looks like the mac's dual link DVI (weather it's 5870 or GT120 since it flickered on both) is outputting a different signal than the PC and the monitor doesn't like it in any position other the tilted up.

    Any ideas cuz I'm all out:(

  6. flatfoot macrumors 65816

    Aug 11, 2009
    Don't know if that's been asked earlier in the thread:
    Are you using the same cable to connect the display to your Mac and the PC?

    I'm sorry for asking such an obvious question, but the tilting problem might actually be in the display-side plug of the cable you're using with your Mac.
  7. kunia thread starter macrumors regular

    Oct 30, 2010
    the 30" apple cinema display has the plug build into the monitor - non replaceable. it's a thick cable that at the end splits into dvi, usb, firewire 400 and a connector that goes into 150w power brick.
    I wiggled the cables at both ends when the monitor was connected to the mac or the pc but it doesn't affected the display. only when I physically tilt the display when hooked up to the mac it goes nuts.
  8. flatfoot macrumors 65816

    Aug 11, 2009
    OK, sorry, never owned one of those displays.

    This is really weird and I hope you or someone else will come about a solution to the problem.
  9. Neodym macrumors 68000


    Jul 5, 2002
    For me that sounds pretty much as if the cable is either broken (data line or shielding) or has bad soldering points inside the ACD. You said you can reproduce the symptom by tilting the display - by doing that you change the angle of the force that the cable puts onto it's internal connectors (soldering points) as well as onto a potential breakpoint inside the cable. Same goes btw. for plugging the cable into another computer - you move the cable in the process and it is then positioned differently which could affect the intensity of the problem.

    As breakpoints are hard to find inside a cable, I would see two options:

    1. Open the ACD and resolder all soldering points of the cable inside the monitor.

    2. Replace the monitor cable completely.

    Both options may not be comfortable for you and I can't judge whether it would be worth it to have it done by a technician (expensive). Maybe you have a friend who could solder for you. I also don't know how easy that soldering inside the ACD may be or if it would be possible at all without special tools. But considering the age of the display you probably don't impair any warranty anymore.

    If you don't want to solder or had enough tinkering with that device, you could also consider selling it as "defective" and have someone else do the soldering, while you get yourself a new 27" Cinema Display, which will probably outperform the 30" by a comfortable margin in terms of brightness and contrast. Though it is glossy and slightly smaller with a slightly lower resolution, so you may still want to give it a try and heat up a soldering iron...
  10. kunia thread starter macrumors regular

    Oct 30, 2010
    I agree that there's a problem with the monitor but ONLY when it's plugged into the mac pro. I can't duplicate it when the monitor is connected to windows xp based PC. Tilting the display up/down or wiggling the cable doesn't produce any static, extensive flickering or blue pixels.

    The question remains...why does it happen on the MP and NOT on the PC.

    btw, from what I've read the new thunderbolt displays do NOT work with 5870 and mac pro.
  11. ActionableMango macrumors G3


    Sep 21, 2010
  12. kunia thread starter macrumors regular

    Oct 30, 2010
    Now I don't know what to do.
    I have an appointment in 6 hours at the apple store. Gotta bring the mac + the monitor, a pain to carry. And since everyone is saying that it's the monitor that's screwed up I dunno if I should cancel.

    Problem is, if I could duplicate what I get on the monitor while connected to the PC (not my mac), I'd know that it's the display at fault and I wouldn't bother with apple store.

    Unless someone tells me that DVI signal coming from the mac is different or more "sensitive" to connection problems than that of a regular PC, hence the flickering issues, I can't assume the display is the problem.
  13. Amazing Iceman macrumors 68040

    Amazing Iceman

    Nov 8, 2008
    Florida, U.S.A.
    Hopefully when you bring it to the Apple Store they may be able to hook up your monitor to another Mac Pro, ruling out your Mac Pro.
    This will simplify the troubleshooting process and save you additional lots of wasted time going in circles trying to figure out this problem.

    Let's just hope it doesn't happen to you what happens to me every time I bring my car to the dealer for service: the problem disappears temporarily, and returns after I leave the dealer.
  14. Neodym macrumors 68000


    Jul 5, 2002
    Even if it is "just" the monitor you should go and have it confirmed by the Apple Genius (and ideally fixed). If he wants to charge you some 500$ for a repair you could still say "no thanks" and try other suggestions from here...
  15. kunia thread starter macrumors regular

    Oct 30, 2010
    last update

    It's the monitor that's at fault. What's interesting about this whole issue is that the DVI signal coming out my mac is much stronger (perhaps different voltage?) than that of my 4 year old PC. On a mac it goes into full static/flashing/flickering blue pixel maze while on the PC I only get a subtle amount of dancing blue pixels.

    As to fixing it, it would cost me 1250$ + tax.'s a non serviceable product, so i'd have to get a refurbished one, and it would come with a 90 day warrant - no thanks:(

    As a temporary solution I've bought their 27" LED. I got two weeks to see if I like it, but so far I'm guessing it'll go back to the store (it's smaller than 30, the cables a to god damn short plus I don't think I'll ever get used to a glossy display). In the meantime I either try to fix the 30" myself or sell it for parts, and look for a new 30" monitor.

  16. theSeb macrumors 604


    Aug 10, 2010
    Poole, England
    Why not the get the Dell Ultrasharp 27"? It has the same resolution as the 27" ACD, is non-glossy and cheaper. Some people complain about the antiglare coating, but I have the 24" version and it's great.

    (please note that I don't do stuff related to photography or movie editing so colour accuracy is frankly is not important to me)
  17. kunia thread starter macrumors regular

    Oct 30, 2010
    The 27" LED is just a temporary quick fix. I have two weeks to return it. I'm probably gonna go with Dell 30" u3011 - I'm used to and want 30" plus I do photo editing.
  18. Neodym macrumors 68000


    Jul 5, 2002
    If at all, it is probably related to the different graphic cards used in the different machines rather than to Mac vs. PC. Possibly the (relatively) new 5870 in your Mac (is it the "official" Apple version btw. or a generic/flashed PC card?) is closer towards the higher end of the DVI specifications, whereas the older card in your PC is more towards the lower end due to component aging etc.

    You can still pry it apart and try some of the mentioned/linked solutions in this thread. Will probably take some time (which is likely why it's not officially serviceable: not economically feasible), so it depends whether you want to spend your time on that or not.

    Alternatively you could get two (non-glossy) 27" displays for nearly the price of one 30" (assuming high resolution at 2560x1440 - with "only" FullHD you can get 3-4 screens at 27") - that way you would not only increase your total screen real estate, but you could also switch to low-power LED technology (the 30" models don't get developed anymore really, so they're stuck in the CCFL age) and improve significantly in the contrast and brightness departments.
  19. xgman macrumors 601


    Aug 6, 2007
    I had a similar problem with a 30" dell monitor. Thought it was everything else but. Finally got a HP 30" and never happened again. A guy with a PC now has my old monitor and never had any issue at all.
  20. puckhead193 macrumors G3


    May 25, 2004
    my brother had the 23" (?) and it would flicker/not sleep... after many trips to the apple store one of the genius suggested it was the white power brick...sure enough it was fixed after years of it not working properly.

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