Can't wakeup iMac when it goes into sleep mode

coylemj

Have a new iMac running OSX 10.6.5, when it goes into sleep mode it just will not wake up. I have tried pressing the spacebar, clicking the mouse, briefly pressing the power button but no dice, it refuses to wake up.

The only way to restart it is to pull out the power lead for 1-2 minutes, then reinsert it and I can switch it on again. I phoned Apple support and the guy told me to hold down some button while powering up, it seemed to fix the problem temporarily but now it's back again, any suggestions?

p.s. The option in Bluetooth/Advanced to 'Allow Bluetooth devices to wake this computer' is switched on, both the keyboard and mouse are Bluetooth connected.

faceman

I had the same problem as you until Snow Leopard came along. Apple was never able to solve it for me nor was anyone online. I have a slightly older 2GHZ iMac.

coylemj

Thanks for that, I'm obviously on Snow Leopard and can't get a solution from Apple either.

I called them again today and got an Irish lady, she talked me through a procedure called 'Resetting the System Management Controller (SMC)' which involves unplugging the power cord and holding down the power button for 5 seconds. After that things seemed to work ok as I was able to put it to sleep and wake it up.

However I then put it to sleep for an hour and can't wake it up so I'm back to where I started.

Sad Professor

I don't really have a solution for you, but a few things:

Try not to pull the plug if possible. Holding down the power button for several seconds is nearly always enough to force a restart.

Do you have any peripherals connected? If so, try disconnecting them. Also, if you have a wired keyboard and mouse on hand it might be interesting to see if the same problem happens with them.

Have you installed any RAM in the machine?

As a last resort you could try doing a clean install of OS X.

However, I would recommend that you continue to pursue this problem with Apple. Your machine may have a hardware problem.

Have you been experiencing this problem since you got the machine, or did it only start recently?

coylemj

Do you have any peripherals connected?

It's often but not always connected to a USB hub though today none of the devices attached to the hub were switched on. There is a joystick attached but I only bought this a few weeks ago and the problem predates it.

Also, if you have a wired keyboard and mouse on hand it might be interesting to see if the same problem happens with them.


I don't have a spare keyboard, my other car is a Porsche machine is a laptop.

Have you installed any RAM in the machine?

Yes but don't tell Apple because they wanted Eur 180, I bought 4GB Kingston DDR3 fully kosher memory for Eur 78 which the machine can see and has no problem with. I did the research and the memory is 100% correct for my machine.

As a last resort you could try doing a clean install of OS X.

I've had this problem since the day I first switched the machine on so this is not an option I'd consider

However, I would recommend that you continue to pursue this problem with Apple. Your machine may have a hardware problem.


I suspect so though another poster had it with an earlier version of OSX and Apple couldn't fix it.

Have you been experiencing this problem since you got the machine, or did it only start recently?

Since day one.

faceman

Hmm actually Sad Professor may be on to something with the peripherals. I switched back to a wired keyboard around the time I upgraded to Snow Leopard so that could be a factor.

Sad Professor

coylemj wrote: »

It's often but not always connected to a USB hub though today none of the devices attached to the hub were switched on. There is a joystick attached but I only bought this a few weeks ago and the problem predates it.

Try disconnecting ALL of them. I'm not saying they are the problem, but this is a process of a elimination and you can't rule out anything.

Yes but don't tell Apple because they wanted Eur 180, I bought 4GB Kingston DDR3 fully kosher memory for Eur 78 which the machine can see and has no problem with. I did the research and the memory is 100% correct for my machine.

It's perfectly okay to install third-party RAM. However, bad RAM can cause all manner of problems. I've been using Macs for years and every single major problem I've ever had was related to third-party RAM that I had installed. There's a reason places like Kingston and Crucial sell their RAM so cheap - they go through less testing, bad chips slip through.

When did you install this?

I would recommend downloading an app called Rember and leaving it running on a loop for several hours.

http://www.kelleycomputing.net/rember/

Also, when you are trying to wake the machine from sleep, can you hear the hard drive spin up? i.e. is it just the screen which isn't waking up?

coylemj

The memory and the joystick were bought a few weeks ago, about 5 weeks after I bought the iMac. I'll try that utility tomorrow.

I had the problem with not being able to wake the machine on the very first day I bought it. I'm familiar with the sleep function on Windows laptops so I wanted to see if it worked the same way.

I don't think the machine is waking at all, one of the problems though with the iMac is that there are no status lights showing you when the disk is being accessed or even if the machine is on or off.

I will disconnect all peripherals tomorrow and test it, I'm familiar with problem determination as a long time ago I was an mainframe systems programmer so I know the procedure. It's just that I'm pretty sure there was nothing connected on day one when I first had a problem trying to wake it from sleep but I'll test it tomorrow with nothing connected.

coylemj

Sad Professor wrote: »

I would recommend downloading an app called Rember and leaving it running on a loop for several hours.

How long does it take to run one loop of Rember? I told it do to 999 loops but after 30 minutes it still hasn't completed one loop and pressing the 'Stop' button doesn't do anything!

Sad Professor

I'm not sure, but it does take a while. I'd just leave it running at night.

coylemj

I killed it and restarted it with a count of '1', it looks like it will take just over 30 minutes so when that's finished I'll let it run for 20 loops.

Liameter

Out of interest, does a quick stab of the power button wake it up?
I have a G4 tower that responds to this method.

coylemj

Liameter wrote: »

Out of interest, does a quick stab of the power button wake it up?
I have a G4 tower that responds to this method.

No it doesn't and if you hold it down for too long it does a boot from scratch.

Liameter

Ah, definitely faulty. It shouldn't reboot. It should shut down if you hold the button and only restart if you press it again.

muggyog

Is this a SMC problem? Have you done the reset mentioned in this article?

coylemj

Yes I did the SMC reset, I also ran the Rember test 16 times and it completed with no errors.

The situation now appears to be that with no peripherals connected it will come out of sleep mode no problem but if I connect up the joystick and a USB hub, it will go to sleep when it times out but will not come out of sleep mode until you pull out the power lead, wait a minute or so, then reconnect the power and it will boot up from scratch.

It's not practical for me to use sleep at all if it involves groping around the back to unplug two USB leads so I am just not going to use sleep at all from now on.

Sad Professor

So it sounds like one of the peripherals is the problem. You could narrow down which one (the USB hub perhaps?) and maybe consider an alternative. If it is causing this problem it could cause others as well. But if sleep is working okay with them disconnected then at least you know the Mac isn't the problem.

muggyog

Apologies, reread thread and see you already did the SMC thing.

You could try creating a new (test) account and see if it is account specific.

coylemj

Sad Professor wrote: »

So it sounds like one of the peripherals is the problem. You could narrow down which one (the USB hub perhaps?) and maybe consider an alternative. If it is causing this problem it could cause others as well. But if sleep is working okay with them disconnected then at least you know the Mac isn't the problem.

SP, thanks for your interest in this but the whole point of the USB hub is so that I can easily switch the external backup drive and the printer between my Windows laptop and the iMac. At some stage in the future I'll probably get a Wi-Fi printer and a NAS drive connected through a LAN hub for sharing but for the moment the USB hub is a permanent feature on my desk.

Given a choice between just never using sleep or having to constantly grope around the back of the iMac to disconnect the hub in order to use sleep, there's no contest. I am just going to permanently disable sleep and I'll shutdown when I'm going to be away from the Mac for more than 30 minutes.