iMac G5: Up In Smoke
by Matt Neuburg <matt@tidbits.com>
http://www.tidbits.com/tb-issues/TidBITS-777.html
This is the story of how my iMac G5 joined the legion of machines that recently have spontaneously failed, and how the problem was resolved.
I purchased my 20-inch iMac G5 at the end of November, and was deliriously happy with it from the start. It crunches numbers in sprightly fashion, runs GarageBand without hiccupping, and even scrolls Microsoft Word documents fairly quickly. It writes DVDs. It has a huge hard disk. The screen displays two full pages of text and is drop-dead gorgeous; it feels worth the price of the entire computer. And then of course there's the astounding form factor: in essence, the computer consists solely of a two-inch-thick monitor, with all the works inside it.
<http://www.apple.com/imac/>
Even before my purchase, I had been hanging out on Apple's discussions boards, where I proceeded to acquire quite an education. For example, I learned that the iMac G5's bus throughput is faster if RAM is installed in matched pairs; therefore I replaced the stock 256 MB of RAM with two 512 MB sticks early in the game. Removing the iMac G5's back cover and installing the RAM was astonishingly easy. Indeed, one of this model's most remarkable features is that it is highly user-repairable. Four internal LEDs assist in diagnosis, and the parts are so ingeniously arranged and connected that, if need be, the user can easily replace the hard drive, the optical drive, the power supply, the inverter, the display, and even the midplane (essentially a sheet of metal to which everything else is attached - replacing the midplane replaces the logic board and fans, and involves removing all the other user-serviceable parts).
<http://discussions.info.apple.com/imacg5/>
<http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G5/iMacG5/04_Expansion/chapter_5_section_1.html>
<http://docs.info.apple.com/article.html?artnum=86812>
<http://docs.info.apple.com/article.html?artnum=300205>
<http://www.info.apple.com/usen/cip/pdf/imacg5/033-2494.pdf>
Intimations of Mortality -- About a month ago I started seeing anecdotal reports, on Apple's discussion boards and elsewhere, that repeated in essence an identical story: iMac G5 users would notice that the machine was giving off an acrid smell, like plastic melting or tires burning, and shortly thereafter the machine would fail. I made a mental note, but I also thought, "This can never happen to me."
<http://discussions.info.apple.com/webx?128@@.68ab823e>
<http://discussions.info.apple.com/webx?128@@.68a4aa56>
<http://www.macintouch.com/imacg5part05.html>
<http://www.macintouch.com/imacg5part06.html>
<http://www.macintouch.com/imacg5part07.html>
But of course it did. On Tuesday, 29-Mar-05, the iMac gave off an ominous smell. It was a foul, slightly nauseating smell, rather like burnt tires; I had to open all the windows just to remain in the room. The fact that I was prepared by the similar reports from other users was suddenly useful. I expected the computer to fail soon, but at that moment it was still running, so I immediately backed it up, twice - once to four DVDs, and again by synchronizing it with my trusty iBook G3/600 that sits in the living room, hooked up to the stereo system. I also ran the Apple Hardware Test (by starting up from a special CD that comes with the computer), and the computer passed all the tests. The next day, Wednesday, the iMac was still running in the morning. I went out to lunch with some friends, and when I returned in the afternoon, the iMac was in a deep sleep from which I could not wake it. I shut it down and couldn't start it up again.
A Doctor in the House -- My first response was (using the iBook) to go onto Apple's iMac G5 support page, where a link leads to a sequence of pages that act as a diagnostic assistant. These pages guided me through an analysis of the situation. At each step, you're presented with a set of choices or questions or instructions, and so you proceed, page by page, to a solution.
<http://www.apple.com/support/imac/>
The assistant elicited from me that the computer was not powering up, that there was no chime, and that the power outlet at the wall was working. It told me to remove the iMac's back cover, plug in the power cord, and examine the four internal LEDs. If the first LED had been off, this would mean I needed a new power supply. But the first LED was on, so the assistant told me to press the internal power button, and then the System Management Unit reset button, to see if the computer would power on. It didn't. The assistant gave its final diagnosis: the mid-plane needed replacing.
<http://www.apple.com/support/imac/assistant/nopower/>
(Incidentally, this series of diagnostic Web pages is both instructional and entertaining. You can learn a lot about your computer just by pursuing an imaginary scenario. For instance, if my computer had started up when I pressed the internal power button, but would not start up when the back cover was replaced, the diagnosis would have been that I needed a new back cover.)
On the last page of the diagnosis, I encountered a pleasant surprise - a link leading seamlessly into the ordering of a new midplane. It looked as though I would solve this entire problem without ever directly contacting a human being. I clicked the link, provided the computer's serial number, and ordered the midplane. You have to supply a credit card number to be charged in case you fail to return the original midplane, but if all goes according to plan, since the computer is under warranty, the entire operation is free. Apple pays for the midplane itself, for shipping the new midplane to you, and for shipping the old midplane back in the same carton (by means of a second label, self-addressed and pre-paid, underneath the carton's label addressed to you).
<http://www.apple.com/support/imac/assistant/nopower/52.html>
Thus, although somewhat disturbed that my computer had failed, I went to bed feeling that Apple's system for handling the situation was commendably efficient.
Second Thoughts -- The next day I woke up and started to worry. I was remembering some more of what I'd read in the user reports on the Internet about various spontaneous failures. Some users had described swollen capacitors, and there was some expert explanation on MacInTouch and elsewhere of how a batch of capacitors with a bad electrolytic formula had been manufactured through industrial espionage, and why this might cause them to swell. But I had seen nothing wrong with any capacitors. Furthermore, those who reported the capacitor problem were also generally reporting flickering displays, along with failure of the Apple Hardware Test, which my computer had passed.
<http://discussions.info.apple.com/webx?128@@.68a31fdd>
<http://www.pbase.com/johncoggi/image/40667990>
<http://g5support.com/group/viewtopic.php?t=4124>
<http://www.oliver-kreuzenbeck.de/iMac_problems/iMac.html>
<http://www.badcaps.com/causes/>
<http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html>
(continued...)
by Matt Neuburg <matt@tidbits.com>
http://www.tidbits.com/tb-issues/TidBITS-777.html
This is the story of how my iMac G5 joined the legion of machines that recently have spontaneously failed, and how the problem was resolved.
I purchased my 20-inch iMac G5 at the end of November, and was deliriously happy with it from the start. It crunches numbers in sprightly fashion, runs GarageBand without hiccupping, and even scrolls Microsoft Word documents fairly quickly. It writes DVDs. It has a huge hard disk. The screen displays two full pages of text and is drop-dead gorgeous; it feels worth the price of the entire computer. And then of course there's the astounding form factor: in essence, the computer consists solely of a two-inch-thick monitor, with all the works inside it.
<http://www.apple.com/imac/>
Even before my purchase, I had been hanging out on Apple's discussions boards, where I proceeded to acquire quite an education. For example, I learned that the iMac G5's bus throughput is faster if RAM is installed in matched pairs; therefore I replaced the stock 256 MB of RAM with two 512 MB sticks early in the game. Removing the iMac G5's back cover and installing the RAM was astonishingly easy. Indeed, one of this model's most remarkable features is that it is highly user-repairable. Four internal LEDs assist in diagnosis, and the parts are so ingeniously arranged and connected that, if need be, the user can easily replace the hard drive, the optical drive, the power supply, the inverter, the display, and even the midplane (essentially a sheet of metal to which everything else is attached - replacing the midplane replaces the logic board and fans, and involves removing all the other user-serviceable parts).
<http://discussions.info.apple.com/imacg5/>
<http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G5/iMacG5/04_Expansion/chapter_5_section_1.html>
<http://docs.info.apple.com/article.html?artnum=86812>
<http://docs.info.apple.com/article.html?artnum=300205>
<http://www.info.apple.com/usen/cip/pdf/imacg5/033-2494.pdf>
Intimations of Mortality -- About a month ago I started seeing anecdotal reports, on Apple's discussion boards and elsewhere, that repeated in essence an identical story: iMac G5 users would notice that the machine was giving off an acrid smell, like plastic melting or tires burning, and shortly thereafter the machine would fail. I made a mental note, but I also thought, "This can never happen to me."
<http://discussions.info.apple.com/webx?128@@.68ab823e>
<http://discussions.info.apple.com/webx?128@@.68a4aa56>
<http://www.macintouch.com/imacg5part05.html>
<http://www.macintouch.com/imacg5part06.html>
<http://www.macintouch.com/imacg5part07.html>
But of course it did. On Tuesday, 29-Mar-05, the iMac gave off an ominous smell. It was a foul, slightly nauseating smell, rather like burnt tires; I had to open all the windows just to remain in the room. The fact that I was prepared by the similar reports from other users was suddenly useful. I expected the computer to fail soon, but at that moment it was still running, so I immediately backed it up, twice - once to four DVDs, and again by synchronizing it with my trusty iBook G3/600 that sits in the living room, hooked up to the stereo system. I also ran the Apple Hardware Test (by starting up from a special CD that comes with the computer), and the computer passed all the tests. The next day, Wednesday, the iMac was still running in the morning. I went out to lunch with some friends, and when I returned in the afternoon, the iMac was in a deep sleep from which I could not wake it. I shut it down and couldn't start it up again.
A Doctor in the House -- My first response was (using the iBook) to go onto Apple's iMac G5 support page, where a link leads to a sequence of pages that act as a diagnostic assistant. These pages guided me through an analysis of the situation. At each step, you're presented with a set of choices or questions or instructions, and so you proceed, page by page, to a solution.
<http://www.apple.com/support/imac/>
The assistant elicited from me that the computer was not powering up, that there was no chime, and that the power outlet at the wall was working. It told me to remove the iMac's back cover, plug in the power cord, and examine the four internal LEDs. If the first LED had been off, this would mean I needed a new power supply. But the first LED was on, so the assistant told me to press the internal power button, and then the System Management Unit reset button, to see if the computer would power on. It didn't. The assistant gave its final diagnosis: the mid-plane needed replacing.
<http://www.apple.com/support/imac/assistant/nopower/>
(Incidentally, this series of diagnostic Web pages is both instructional and entertaining. You can learn a lot about your computer just by pursuing an imaginary scenario. For instance, if my computer had started up when I pressed the internal power button, but would not start up when the back cover was replaced, the diagnosis would have been that I needed a new back cover.)
On the last page of the diagnosis, I encountered a pleasant surprise - a link leading seamlessly into the ordering of a new midplane. It looked as though I would solve this entire problem without ever directly contacting a human being. I clicked the link, provided the computer's serial number, and ordered the midplane. You have to supply a credit card number to be charged in case you fail to return the original midplane, but if all goes according to plan, since the computer is under warranty, the entire operation is free. Apple pays for the midplane itself, for shipping the new midplane to you, and for shipping the old midplane back in the same carton (by means of a second label, self-addressed and pre-paid, underneath the carton's label addressed to you).
<http://www.apple.com/support/imac/assistant/nopower/52.html>
Thus, although somewhat disturbed that my computer had failed, I went to bed feeling that Apple's system for handling the situation was commendably efficient.
Second Thoughts -- The next day I woke up and started to worry. I was remembering some more of what I'd read in the user reports on the Internet about various spontaneous failures. Some users had described swollen capacitors, and there was some expert explanation on MacInTouch and elsewhere of how a batch of capacitors with a bad electrolytic formula had been manufactured through industrial espionage, and why this might cause them to swell. But I had seen nothing wrong with any capacitors. Furthermore, those who reported the capacitor problem were also generally reporting flickering displays, along with failure of the Apple Hardware Test, which my computer had passed.
<http://discussions.info.apple.com/webx?128@@.68a31fdd>
<http://www.pbase.com/johncoggi/image/40667990>
<http://g5support.com/group/viewtopic.php?t=4124>
<http://www.oliver-kreuzenbeck.de/iMac_problems/iMac.html>
<http://www.badcaps.com/causes/>
<http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html>
(continued...)