2011 iMac i5 Won't Start

[robastewart]

iMac won't start after routine sleep mode. Walked away from machine as usual. It is set to sleep after 15 minutes. But coming back to it several hours later it is just dead. No power indicated when pressing the power button.

Thoughts please?

Thank you.

 

[xraydoc]

iMac won't start after routine sleep mode. Walked away from machine as usual. It is set to sleep after 15 minutes. But coming back to it several hours later it is just dead. No power indicated when pressing the power button.

Thoughts please?

Thank you.

Try unplugging it from the AC for at least 15 seconds, unplugging all peripherals except keyboard and mouse, then trying to turn it back on. If nothing at that point (and you know the AC outlet is good and doesn't have a blown fuse/circuit breaker), then your computer is going to need some professional attention.

 

[robastewart]

Try unplugging it from the AC for at least 15 seconds, unplugging all peripherals except keyboard and mouse, then trying to turn it back on. If nothing at that point (and you know the AC outlet is good and doesn't have a blown fuse/circuit breaker), then your computer is going to need some professional attention.

Okay. Thanks. Have tried all the recommended home remedies to no success and agree with you that professional attention is needed. Just got back from taking it in to Simply Mac for diagnosis and repair. Should know something in a couple days.

 

[Altemose]

Okay. Thanks. Have tried all the recommended home remedies to no success and agree with you that professional attention is needed. Just got back from taking it in to Simply Mac for diagnosis and repair. Should know something in a couple days.

When you try doing the unplugging you should also have tried holding power for 30 second as you plugged it in. This will perform a reset of the SMC.

 

[DeltaMac]

I usually avoid correcting posts, but that's the wrong method to do an SMC reset:
Don't hold the power button in, while connecting the power cord.
http://support.apple.com/kb/TS1433

It's like this:

Attach the computer’s power cord, making sure power button is not being pressed. Note: If you press the power button while inserting the power cord, the iMac will enter a mode in which the fans run at full speed.

(There have been a couple of Mac models that process will help, iMac G5 I think, but not since Apple moved from PPC to intel processors)