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Re: iMac power problem

Posted: Sat Sep 08, 2012 12:15 pm
by frankie big face

Re: iMac power problem

Posted: Sat Sep 08, 2012 3:32 pm
by Caravan Ray
frankie big face wrote:Reset the SMU:

http://support.apple.com/kb/HT1767?view ... cale=en_US
Done it repeatedly. No good.

Re: iMac power problem

Posted: Mon Sep 10, 2012 1:53 pm
by AJOwens
I know nothing about Macs, but I love a good mystery.

One page I consulted seemed to think it was very important to unplug the power cord at the unit, not at the wall outlet. They didn't say why.
http://forums.macrumors.com/showthread.php?t=987528

Another suggested that depending on your model, the System Management reset may be triggered by an ambient light sensor when you unplug the unit.
http://www.justanswer.com/mac-computers ... won-t.html

So I gotta ask: Which end of the power cord are you unplugging when you try the fix that doesn't work?

Re: iMac power problem

Posted: Mon Sep 10, 2012 2:20 pm
by Caravan Ray
AJOwens wrote:I know nothing about Macs, but I love a good mystery.

One page I consulted seemed to think it was very important to unplug the power cord at the unit, not at the wall outlet. They didn't say why.
http://forums.macrumors.com/showthread.php?t=987528

Another suggested that depending on your model, the System Management reset may be triggered by an ambient light sensor when you unplug the unit.
http://www.justanswer.com/mac-computers ... won-t.html

So I gotta ask: Which end of the power cord are you unplugging when you try the fix that doesn't work?
I think I have pretty much tried every combination and permutation.
I have been trawling the various mac user forums for months now and found a lot of different variations of cord pulling and button pushing. Tried all of them.

I think there is just something wrong with whatever does the 'reset' thing. I have found in some of those forums comments from people with what sounds like exactly the same problem

Re: iMac power problem

Posted: Mon Sep 10, 2012 2:27 pm
by AJOwens
OK, here's a wild shot. Inspect the AC receptacle area to see if you can find a light sensor. If so, try cleaning it. God knows what kind of gunk could be stuck there! :-)

Re: iMac power problem

Posted: Tue Sep 18, 2012 12:08 am
by fluffy
AJOwens wrote:I know nothing about Macs, but I love a good mystery.

One page I consulted seemed to think it was very important to unplug the power cord at the unit, not at the wall outlet. They didn't say why.
http://forums.macrumors.com/showthread.php?t=987528
Because computers are apparently products of voodoo and not science/engineering. There is absolutely no reason that would make any difference whatsoever.

If it's not the PRAM or the SMU, maybe it's the PRAM battery? If you can get the darn thing open try replacing it.

Re: iMac power problem

Posted: Wed Sep 19, 2012 9:27 am
by AJOwens
These days you just never know. I still remember my surprise when I learned that my Windows speaker settings were disabled because the the sound card jack wasn't occupied.