Home Forums Hardware Mac Desktops & Notebooks Early 2006 iMac power button nonresponsive

The power cord accidentally pulled out of the back of my early 2006 20-inch Intel iMac, causing the computer to shut down suddenly. When I replaced it, I was unable to start the iMac. I press the power button and nothing happens. Nothing at all.

Any suggestions?

Thank you.

Hi Bob,

Read Intel-based iMac: What to do if your computer won't turn on. I suspect that resetting SMC (there is a link in that article) will turn the trick.

Thanks, Jon. Before you responded to my post, I took the iMac into my wife's office to attach her USB keyboard to it (my keyboard is bluetooth, and I hoped that pressing some key combination while depressing the power button might help).

Oddly enough, as soon as I attached her keyboard and touched the power button, my iMac started up just fine. It continues to run fine now. I've restarted a few times without any problem.

I had previously tried switching power cords and using outlets in different rooms, without success. Whether or why attaching a keyboard should make any difference, I know not.

Oddly enough, at the same time this was happening, my Dell monitor (which I use for additional screen space) stopped working entirely. It's toast. So I'm wondering whether there was some kind of power surge which affected both devices. Both are plugged into a high-end surge protector, for whatever that's worth.

In any case, the monitor was pretty inexpensive, whereas to replace the iMac would be considerably more expensive. So I'm not at all unhappy with the outcome.

Thanks for the suggestion about resetting SMC. That very probably would have worked.

Jon, it just happened again! The iMac suddenly died while in use, and would not restart (SMC reset notwithstanding). I changed power cords, power outlets, rooms, nothing helped. So I unplugged it, and let it sit unplugged for 24 hours. I then plugged it in, pressed the power button, and it started and has worked without further problems for a couple of days now.

To further confuse the issue: iMacs have a little light below the screen which is invisible while the computer is on and running, but which shows up and flashes bright and then dim while the machine is sleeping. When this computer is allowed to sleep for a while, the little light stops dimming... it stays bright until awakened.

Could that be a clue? To what?

It could be a clue that an appointment with a "Genius" is in your future. (They have diagnostic tools that are unavailable to us mere mortals.)

In no particular order...

Have you looked in /Apps/Utils/Console to see if any messages were posted at about the time of the quits?

Have you tried logging in to a test user account to see if your iMac quits on that account too? (Not likely to be/have been productive. )

Have your run the Apple Hardware Test? (I'm not certain which format shipped with your iMac.)

Booklaw I am sure this is not what you want to hear, but I recently had a similar problem with my iMac. In my case the first symptoms seen were problems when rebooting, then progressed to sudden death/lockup scenarios. It turned out to be heat related and when the iMac was relatively cool, not working too hard, everything was fine. However when it was stressed, doing lots of heavy processing and substantial levels of I/O and the internal temp reached a certain point － zap. Allowing a cool down period would temporarily restore functionality.

The length of the cool down kept getting longer and the periods between blackouts shorter until I took it to the Genius Desk where they replaced the Video Card, Logic Board, and Power Supply (the hard drive had already been replaced several months ago after it failed). The net list price of the repairs amounted to about $200 less than a new high end iMac but thanks to AppleCare my entire cost was $0.00 － free. That is the best argument for AppleCare I can think of.

I wonder if you're not seeing one of the green diagnostic lights that's on the logic board, it may be visible given the perfect angle. There are 3-4 of them, one is trickle, one is logic board on, and one is LCD communications. They're green.

Virtual, no this is a white light. The newest iMacs (such as my 27" iMac) do not have this light, but my earlier G5 and early 2006 Intel iMac each had one, on the right side of the front in the middle of the white plastic bottom below the screen.

We had a similar experience earlier this year when the old G5 iMac also died, then recovered, and then finally died again... turned out it needed a new logic board.

Artie and JoeMike, I expect I'll be bringing it in for diagnosis shortly. My Applecare expired about a year ago... so I'll probably end up replacing the machine, rather than repairing it (unless it turns out to be something relatively inexpensive, such as a power supply).

Good luck!

... and good luck it was!

$271 for a power supply, and we're up and running. That's what I had hoped for.