20" ACD red pixel flickering...

Discussion in 'Mac Accessories' started by BustedMac, Aug 5, 2009.

  1. BustedMac macrumors newbie

    Aug 5, 2009
    Hello Everyone,
    I am a first time poster but a long time reader of the board. I would like to see if anyone can offer any insight to my problem.

    Last week I purchased a 20" Apple Cinema Display from Best Buy, it was a display model from the sales floor, looked amazing, I was actually looking for a 23" NOS but they gave me the 20" at a price I could just not refuse.

    It was working great till last night, it begin to flicker certain pixels red where they should be black. Usually around the source of motion, for example the screen saver, the edges of the effect would flicker red instead of being black like the background. This was very minor at first but would progress to the whole black area flickering red, then go away, come back, so on and so forth. It actually did it once or twice when I brought it home but it was very minor and I dismissed it as being in my head, one of those "did I really see that?" type of moments.

    Best Buy doesn't have any more in stock so they cannot replace it, they suggested I contact Apple for warranty support. Apple's website says the unit is out of warranty but I have sent them the sales receipt so they can update my purchase date, at which time, I should be covered and hopefully get my display repaired because I really do like it and it matches my office quite nicely.

    My questions is regarding the worst case scenario, where my display is not repaired/replaced by Apple.

    Has anyone had any luck determining the cause of these anomalies?

    Apparently the flickering pixels is common among the older ACD family so I was wondering if the fix was out there. Maybe a revision "b" part of some sort that takes care of the defect.

    My instincts tell me it's some sort of EMI/RFI issue, maybe improper shielding on something. Maybe a result of the power, dvi, usb, and firewire all being in the same sheaf. I'm sure the cable is shielded but maybe it's something that proved to be in adequate in certain environments and so a newer revised cable was released. I don't know, I'm just thinking out loud here.

    I tested the display on my MacBook Pro, MacBook with the Mini-DVI to DVI adapter, and a Dell Desktop I have with an Nvidia card and the result is the same with all three computers so I'm sure it's the display.

    The display is plugged into a UPS but it does the same thing when not plugged into the UPS in a different outlet in my home. I tired to move it around to different breakers to see if it was isolated to a certain outlet/breaker in my home, but they all give the same results.

    I think I have an old ISOBar (power filtering power strip) somewhere I could try to see if it's a dirty power issue but my other monitors didn't seem to mind it if there is indeed a noise problem with my home's power.

    I don't know... I would love to hear the thoughts of other users who have had and dealt with similar issues with their ACD.

    Thank you everyone for your time.
  2. BustedMac thread starter macrumors newbie

    Aug 5, 2009
    I was able to identify that the problem with the dancing pixels I am experiencing is a physical problem. Grabbing the base with one hand and pushing or pulling on the controls side of the monitor would make the problem go away.

    I realized it was physical when my son bumped my computer table and it went all crazy.

    I found some pictures of an ACD taken apart on the internet and I have noticed that the cable breaks out into several smaller cables that route to a main board of sorts inside the display. These appear to be the signal cables for the DVI portion of the one "Super" cable.

    My new hypothesis is that expansion and contraction over this displays show room life as a result of heating up and cooling down has maybe made one or all of these connections weak, maybe unseated slightly. Maybe there's some dry solder cracks in there. I won't know until I take it apart and I'm not touching it until I get a response from Apple on my warranty status (still no reply but they have till Monday as per their guidelines for purchase date updates). But I can at least work on it now since I found the sweet spot to get me by.

    Anyone with any thoughts, similar experiences, and etc. please feel free to chime in.

    I will update the board when I have something new.

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