Cold booting my new iMac

Recently I've had to press the power button twice every time I boot it on. I can press the power button once consistently to put it into sleep mode. So could this be a software issue? For weeks when I first got it I would only need to lightly press the power button once to boot it on.

Other than that the iMac's been great. Always been an Apple fan (hardware/apps).

Try pressing it firmly once and then step away for a few seconds before pressing again.

I've found my own impatience has led me to think the same thing of a number of devices I own that have "soft" power switches like this.

As far as cold-booting goes, I would suggest you stop shutting it down entirely. The Sleep mode consumes almost no power and allows for instant wake without having to use the power button at all.

cwa107,

I will try that next time. Though, when I first got it, I didn't have to press it "firmly" and got it to boot up. 1 button press.

Perhaps, recently I've been pressing the button too lightly early in the morning booting up for the first time that day.

Now it's powering up on the 2nd press. I think with the same pressure on the button. And as I said I never had a problem pressing the power button once to put it in sleep mode. Which is why I'm wondering if this isn't a software issue. If it was the button then I should have to press the button more than once to put it into sleep mode too.

And once it's been cold booted. I can shut it off. Wait. Then power it up with 1 button press. Though when I do this I usually hear a "click, CLICK".

Not shutting it down at all? Only problem with that is I'd be concerned about a possible power spike. I usually power down at the end of the day. Then shut off my power bar so no power goes to my computer gear. But during the day I leave my iMac in sleep mode.

That's a good point - if you sleep it all the time, you may have issues should you lose power. Hadn't really thought about that as I'm using a laptop.

I don't think this is a software issue though, to be honest. I would try resetting PRAM first and then the SMC if the problem continues. To reset the PRAM, turn the machine off. Turn it on and immediately press and hold Command + Option + P + R. Continue holding until the machine chimes twice. Then, release. See if the issue persists after that.

Why would I want to reset the "PRAM first then the SMC"?

Following your steps is the "SMC" reset too?

Also, in resetting the "PRAM" what happens to all the data on my HDD and settings?

BDD888 said:

Why would I want to reset the "PRAM first then the SMC"?

Following your steps is the "SMC" reset too?

Also, in resetting the "PRAM" what happens to all the data on my HDD and settings?

Click to expand...

PRAM is non-volatile memory that stores certain settings specific to EFI. From time to time, those settings can become corrupt and a PRAM reset sets it back to factory defaults. It does *not* have any bearing on your data or operating system and can sometimes cure some of these low-level, pre-boot issues.

The SMC (Systems Management Controller) stores data about power management and can sometimes benefit from a reset - but this is less likely to be needed on a desktop machine. The steps mentioned do not reset the SMC - I'm actually not sure how to do that (or if there would be any benefit) on an iMac.

Ok thanks cwa107. Quick response.

What is EFI?

BDD888 said:

Ok thanks cwa107. Quick response.

What is EFI?

Click to expand...

Extensible Firmware Interface. If you're familiar with BIOS on the PC, it performs a similar role.

Basically, your computer's mission in life is to run programs. Without a program, it can't do anything. So, when you first power on, memory is empty and there aren't any programs to run - so how does your Mac know what to do? The answer is EFI (and BIOS on most PCs). It's basically a very tiny little operating system that initializes immediately upon power-on and does a few quick tests, then tells the system how to boot the main operating system.

This is a very simplistic explanation. If you need something more detailed, have a look at Wikipedia here.

Thanks for the explanation cwa107. Pressing those key combinations only resets the PRAM right? How would I reset the EFI? (if resetting the PRAM doesn't help).

Also, some one from another forum just suggested I try holding the power button a few seconds till I hear the fans kick in. Said that's what he's been doing.

As I said when I first got my iMac I'd only press once. Quick press.

BDD888 said:

Thanks for the explanation cwa107. Pressing those key combinations only resets the PRAM right? How would I reset the EFI? (if resetting the PRAM doesn't help).

Click to expand...

That's correct.

Instructions for resetting the SMC:

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Press and hold the power button for 5 seconds.
4. Release the power button.
5. Attach the computers power cable.
6. Press the power button to turn on the computer.

Also, some one from another forum just suggested I try holding the power button a few seconds till I hear the fans kick in. Said that's what he's been doing.

As I said when I first got my iMac I'd only press once. Quick press.

Click to expand...

As far as I know, that shouldn't hurt anything - but then again, it shouldn't need more than a quick (firm) press.

Thanks cwa107.

You can reset the EFI with no power??

BDD888 said:

Thanks cwa107.

You can reset the EFI with no power??

Click to expand...

Even with the cord pulled, your iMac still has power from the CMOS battery.