imac power up problems.

[Alfregdavitt]

My 2011 imac won’t power up after being disconnected from wall electric outlet. The imac works perfectly fine other than doing this. I have left it with apple for a week and they said there is nothing wrong with it. They said it came on and worked perfectly when they unplugged it. If I unplug it, while it’s off, and later plug it back in its totally dead. But after a few days it will power up fine and work totally normally until the next time its unplugged.

 

[ferrarr]

Have you tried other outlets (plugs) in your home? It does sound like a power, coming into the iMac, issue.

 

[Alfregdavitt]

Hi, Thank you for your response. Yes I have tried other plugs in my house and I have tried plugs in friends houses also with different power leads none have worked. What ever I do the imac is totally dead for two or three days following disconnection from the power.

 

[RadDave]

Hi, Thank you for your response. Yes I have tried other plugs in my house and I have tried plugs in friends houses also with different power leads none have worked. What ever I do the imac is totally dead for two or three days following disconnection from the power.

Well, I'm sure that this was done at the Apple store (or by you), but has SMC (System Management Controller) been reset? If not, check the link - a simple maneuver which I had to used on my MBPro after a recent macOS update due to a sleep issue not working right - issue was corrected. Dave

 

[Alfregdavitt]

Just did the smc reset sequence now it won't power up, it's dead because it's been unplugged. The start of the two or three days until it powers up again starts.

 

[chscag]

Sounds like the power supply is failing. Take it back to the Apple Store and have them run tests on the power supply.

 

[dtravis7]

Agree with Chscag, if the SMC reset did not fix it, it sounds like a Capacitor going in the Power Supply.

 

[pm-r]

My 2011 imac won’t power up after being disconnected from wall electric outlet.

Maybe I'm missing something but there's not one iMac model ever produced that will boot when disconnected from a power source.
And "I have left it with apple for a week and they said there is nothing wrong with it".

Have you checked the actual electrical power receptacle that there's power available with a proper power multi tester and/or the power cord is not faulty???






- Patrick
======

 

[dtravis7]

Patrick, what he is saying is if he UNplugs it then plugs it back in it will then not power up. I have seen that with many of the Alluminum iMacs. Usually an SMC reset fixes it but he tried and still acting up.

It sounds like a capacitor that is bad to me.

 

[pm-r]

Patrick, what he is saying is if he UNplugs it then plugs it back in it will then not power up.

OK, but maybe just don't unplug it in the first place, or is this like the case to leave the device unpowered for a while to let things stabilize…

I seem to recall some of the old Classic and PowerMacs behaving the same way, and putting them outside overnight in the colder air would have them booting and working in the morning. And that was the fix in those days!! Then the sharp rubber mallet whack also became popular…


EDIT:
I thought the iMacs got rid of their bad capacitor problems almost ten years ago now. ???





- Patrick
======