David Anders,The Computer Guy, a freelance systems engineer in Seattle, WA.
Resolves computer problems, assists with production issues, designs and installs networks.
iMac "green light of death" is more than a wake-from-sleep problem
We have previously documented a failure of the iMac (especially older Revision A and B models) to wake from sleep (the screen remains black and usually the power light on the iMac turns orange). However, we were less familiar with a similar sort of problem that can occur at startup (with no sleep command involved). In particular, the symptom is that the green light on the front of the iMac comes on at startup (indicating that things should be going well), but the monitor stays dark and never comes on. A relative of ours had this happen to their iMac. The only way they could reliably bring it back to life was by unplugging the machine from the wall outlet (and then plugging it back in). But the problem would return by the next day.
We have since learned that this problem is common enough that it has been named the "the green light of death" on Apple's Tech Exchange Forums. There are numerous postings on this subject (as a search on the term "green light of death" reveals). Two good starting threads are a and b.
In our case, we called Apple Support for help. They said that the analog/video board needed to be replaced (this is consistent with a previous report here). We got it replaced and all was well. Other users have reported that Apple told them their logic board needed to be replaced. Whatever the case, if you have this symptom, a hardware repair is needed. Contact Apple or your authorized service provider.
Green light of death: a follow-up
. Our report last time on the "green light of death" triggered numerous replies from readers. The summary is that this problem extends beyond the iMac to the Apple Studio Display monitors. It also reminded several readers of similar problems (and similar solutions involving the analog board on the monitor) with the AppleVision 1710 monitor several years ago. It makes you wonder why Apple can't seem to get this solved once and for all.
Bob O'Driscoll clearly describes the general problem on an iMac: "With my Rev B iMac, when you shut it down, the shut down appears normal except that the green light remains on. On restart, it makes appropriate startup noises but the screen remains blank. The same behavior follows restart or sleep. The work around after shut down is to remove the power until the green light goes out. The iMac can then be restarted normally. The problem is also intermittent in that it very occasionally does shut down properly. The Apple dealer diagnosed the problem as the power supply board and has ordered that part."
Danny Murtaugh has a 17" Studio Display that will not wake up from sleep. Same thing with the monitor light also happens. He spoke with Apple and they had him try holding down the Command-Option-A-V keys on restart - but it did not work.
Ola Hansen had the same wake-from-sleep problem on his 17" Studio Display. Using Sleeper instead of Energy Saver did not help. Apple Support told him to try re-installing the Mac OS (I guess this was not a well-informed support tech).
Scott Boettcher writes: "I had the same issue with three 21" Apple Studio Displays. After three-four weeks of working wonderfully, they just die. Black screen, green light. They all have had to go back and get a 'main deflection board' replaced which is (surprise) in short supply!"
Matthew Strange reports that replacing the analog/video board did not eliminate this symptom on his iMac. For the Studio Display, he writes: "This exact same thing happened to one of my clients. Apple Support had him plug the monitor directly into a wall outlet and that fixed it. It seems that the claim is that when everything is waking up from sleep at the same time, the competition for AC causes the monitor to lose the battle and go back to sleep!" [I am skeptical!]
Linda Katz notes: "I experience the same thing on my (beige) ColorSync 21" monitor with 333 beige G3! I manually turn the monitor on and off every time - at start, restart and waking from sleep or Energy Saver. But - this has only started happening since I upgraded from Mac OS 8.5.1 to 8.6!"
Deleting the Display Preferences file within the Preference folder solved this problem for David Brock.
TIL article on iMac stall is pulled Apple has pulled the TIL article about iMacs stalling when the CD/DVD driver is enabled (see also this MacFixIt item). This may be because the iMac CD Firmware Update 2.0 supposedly fixes this problem (see this MacFixIt item). Still, you would think they would update the article to reflect the fix, rather than simply delete it. Odd. (Thanks, Dave Merten.)
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