IMac screen blanking problem

Posted:
in Genius Bar edited January 2014
Hi All,



I'm a proud owner of a brand new 20", 2.6 GHz IMac. The machine worked beutifully for one day, after which the problems started.

For no apparent reason at all, the screen would go almost completely black. This isn't just dim, there is *almost* no image whatsoever (I didn't even notice the faint image at first, thinking the machine had simply shut off). This was not a case of screen dimming for power save, I had the feature disabled. I re-booted the machine, but the screen went "dead" within minutes again. Repeating the process, same results.



I took the computer to my local Apple store, where they replaced it for a new (identical) machine. Everything was great for a few days. Yesterday, the new machine did the exact same thing - virtually black screen, only re-boot helps.



My impression is that the problem appears if the monitor (or other) temperature gets too high; the problem only appears after a couple of hours of work, but once it appears, it re-appears quickly (unless the machine has had time to cool down).



Has anyone else seen a problem like this? I really don't want to exchange the machine again, without *some* confidence that the problem will be resolved.



Thank you very much!



Sincerely,



Borna

Comments

  • Reply 1 of 1
    toymakertoymaker Posts: 30member
    Quote:
    Originally Posted by Borna View Post


    Hi All,



    I'm a proud owner of a brand new 20", 2.6 GHz IMac. The machine worked beutifully for one day, after which the problems started.

    For no apparent reason at all, the screen would go almost completely black. This isn't just dim, there is *almost* no image whatsoever (I didn't even notice the faint image at first, thinking the machine had simply shut off). This was not a case of screen dimming for power save, I had the feature disabled. I re-booted the machine, but the screen went "dead" within minutes again. Repeating the process, same results.



    I took the computer to my local Apple store, where they replaced it for a new (identical) machine. Everything was great for a few days. Yesterday, the new machine did the exact same thing - virtually black screen, only re-boot helps.



    My impression is that the problem appears if the monitor (or other) temperature gets too high; the problem only appears after a couple of hours of work, but once it appears, it re-appears quickly (unless the machine has had time to cool down).



    Has anyone else seen a problem like this? I really don't want to exchange the machine again, without *some* confidence that the problem will be resolved.



    Thank you very much!



    Sincerely,



    Borna



    If the screen is going ALMOST completely black, ie, there is a very feint image but it isn't illuminated, it's possible that the power inverter for the LCD is faulty (and, if it's a design fault, it would explain that both of the units may have had the same fault). Of course you should try turning up the brightness using both the keyboard keys and in system preferances so you can definately rule that out (I know you said you had the auto dim turned off, but 10.5 does strange things that it isn't supposed to do sometimes)



    When you got the replacement, did you copy your data back from your original mac, or start with a fresh OS? If you copied the OS from your old mac (or the techs at the shop simply swapped your original hard disk into the new machine) I would first try booting onto the system disks that came with the mac.



    If it still happens when booted from the disks, it means it's almost certainly a hardware fault and you should take the Mac back to the store for repair or replacement. If it does not happen, it means it's likely a problem with the OS install, and I would back up your data, wipe the hard disk clean and reinstall the OS.
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