iMAC dead in the morning

If I leave my 21 inch all in one iMAC on at bedtime in the morning the screen is black but the computer is warm. the only way i have found to get it to work again is to unplug the power cord and plug it back in.

Paul in Toledo said:

If I leave my 21 inch all in one iMAC on at bedtime in the morning the screen is black but the computer is warm. the only way i have found to get it to work again is to unplug the power cord and plug it back in.

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Which iMac? What version OS X?

OS X 10.9.2

3.2 gHz Intel Core i3
4 GB 1333MHz DDR3
Graphics ATI Radeon HD 5670 512 MB

You're saying that the iMac is sleeping but it won't wake unless you unplug it and plug it back in? In other words, it's powered up, but the screen is off and the hard drive is not spinning?

Do you happen to have "Wake for network access" (better known as "Wake on LAN") enabled in the Energy Saver preference panel? If so, disable it. There is a bug in Mavericks where the OS will lock up while sleeping if enabled. I'm experiencing it also, and rooting it out was maddening.

I have that particular item checked in my Energy Saver power settings and have not experienced the bug you refer to. Running Mavericks 10.9.3 on a 2013 27" iMac. Does Apple have anything to say about it?

chscag said:

I have that particular item checked in my Energy Saver power settings and have not experienced the bug you refer to. Running Mavericks 10.9.3 on a 2013 27" iMac. Does Apple have anything to say about it?

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Seriously? I'm not sure what Apple has to say about it... maybe it only affects certain Macs. There was another thread here and MacInWin was familiar with it also. I haven't tried to see if it was fixed in 10.9.3 yet. I'll test it out tomorrow.

As far as I can remember, I've had that item checked off in Energy Savings preferences since the day I turned on the iMac when I got it last November. It may be a combination of things that cause it not just the wake on lan by itself.

chscag said:

As far as I can remember, I've had that item checked off in Energy Savings preferences since the day I turned on the iMac when I got it last November. It may be a combination of things that cause it not just the wake on lan by itself.

Click to expand...

It could be. I gave up trying once I narrowed it down to that preference and simply left it off. I literally spent weeks beating my head against a wall until I decided to look at the logs and quickly saw what the problem was.

Anywho, it appears that 10.9.3 has resolved this problem on my end. No lockups all weekend with WOL re-enabled.

So, back to Paul... update to 10.9.3 and see if that resolves your problem.

thanks I unchecked it & will see what happens then try updating

I would update to 10.9.3 also since you have 10.9.2 listed.

July 1 I updated to 10.9.3 and the problem hasn't recurred. thank you.

Check your current OS X versions number. Apple released 10.9.4 yesterday/last night. It contained a few more networking and wake from sleep fixes.

Now update to OS X.9.4 as Slu suggests. Important things these updates.