iMac Keeps Waking up for no apparent reason!

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
We have a new iMac, but for some reason, it comes out of sleep all by itself. In the middle of the night, the monitor comes on, then goes off, then comes back on later, ....

The only program running (according to Command-Tab) is Finder.

Any reason why this could be happening and what we can do to fix it (keep the mac asleep)?

Thanks in advance for any help or suggestions.

- M
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
Check your Energy Saving settings and repair your permissions with Disk Utility. If it still continues, restart it and don't open any apps but put it to sleep and see if it wakes up (this is to eliminate possibility of software glitch/bug)
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
Thanks for your reply.

What in particular about the energy saver settings would cause this?

Thanks.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
Thanks for your reply.

What in particular about the energy saver settings would cause this?

Thanks.
Wake up in network connection or from preset options (bottom right corner) if you have set it to wake up at certain time.

Sorry if my setting names aren't the same as I'm using OS X in Finnish.
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
Thanks!

Disk utility didn't seem to find anything, but I did a reboot and will wait and see. Thanks.
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
New Problem

Actually,

now we can't get the iMac to go to sleep at all.

Click the apple, click sleep.

The display flashes (like it "wants" to go to sleep), but then comes right back on.

Could this be a hardware problem?

This is a brand new machine. Time to call Apple?

-- M
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
Actually,

now we can't get the iMac to go to sleep at all.

Click the apple, click sleep.

The display flashes (like it "wants" to go to sleep), but then comes right back on.

Could this be a hardware problem?

This is a brand new machine. Time to call Apple?

-- M
I agree with dsnort. It's not your job to solve problems. Call Apple and get it fixed
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
Thanks.

A quick Google search shows that this is a common problem, with no, as I saw, definitive solution.

:(

- M
 

Fishrrman

macrumors P6
Feb 20, 2009
17,207
5,550
"A quick Google search shows that this is a common problem, with no, as I saw, definitive solution."

There IS a "definitive solution". One that will work, 100% guaranteed.

Here's what to do:
1. Hook the iMac up to a power strip or surge protector with an on/off switch.
2. At night, don't put the iMac "to sleep". Instead, choose to "shut down".
3. When the iMac goes dark, reach down and flip the switch on the power strip to OFF.
4. In the morning, reach down and flip the power strip ON, then press the iMac's power-on button.

Do this, and you will NEVER be bothered by the iMac "waking up" in the middle of the night. 100% certainty.
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
"A quick Google search shows that this is a common problem, with no, as I saw, definitive solution."

There IS a "definitive solution". One that will work, 100% guaranteed.

Here's what to do:
1. Hook the iMac up to a power strip or surge protector with an on/off switch.
2. At night, don't put the iMac "to sleep". Instead, choose to "shut down".
3. When the iMac goes dark, reach down and flip the switch on the power strip to OFF.
4. In the morning, reach down and flip the power strip ON, then press the iMac's power-on button.

Do this, and you will NEVER be bothered by the iMac "waking up" in the middle of the night. 100% certainty.
Very funny. :)
 

Fishrrman

macrumors P6
Feb 20, 2009
17,207
5,550
"Very funny"

Wasn't intended to be "funny".

I was serious. That's exactly what I do with both my Macs.
 

talmy

macrumors 601
Oct 26, 2009
4,703
266
Oregon
I had a problem with my new iMac constantly waking up from sleep. It turned out to be a bot trying to hack into my SSH port I keep open for remote access. I'd suggest disconnecting the network connection and seeing if the computer starts sleeping. If so, there is network activity waking it up.

I closed the port and now it sleeps like a baby.
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
I'm incredibly surprised no has told him to look at Console logs.
The solution for us turned out to be just unplugging the USB cable that goes to an old HP 6 LaserJet printer.

Even though the printer was OFF, as soon as I unplugged the USB cable from the back of the iMac, it went right to sleep.

Weird, but fixed.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
The solution for us turned out to be just unplugging the USB cable that goes to an old HP 6 LaserJet printer.

Even though the printer was OFF, as soon as I unplugged the USB cable from the back of the iMac, it went right to sleep.

Weird, but fixed.
If it's old, the driver is probably not made for Snow Leopard (you have it right?) so that's causing it.
 

SaSaSushi

macrumors 601
Aug 8, 2007
4,079
470
Takamatsu, Japan
Glad to hear you tracked it down to the older printer.

I've noticed that any USB activity whatsoever will wake up a Mac. That is to say that if I put my iMac to sleep and then notice I forgot to power off my Canon MP960 printer, just hitting the power button on the printer to shut it off will instantly wake up the iMac. It's not limited to USB either. I use the SPDIF out via mini-TOSLINK cable to connect the Mac to a home theater and turning the receiver off and on will wake the machine.
 

SaSaSushi

macrumors 601
Aug 8, 2007
4,079
470
Takamatsu, Japan
I'm not sure then what the point is of having "new HP drivers" in 10.6.2 then... ????
Was that mentioned? I did have a look at HP's site. Is yours the 6P?

They do indeed claim SL drivers come with the OS.

You've absolutely confirmed the printer to be the cause of your Mac's sleep disturbances so I suppose you could either just leave it disconnected while sleeping or contact HP for support.
 

Mork

macrumors 6502
Original poster
Jan 9, 2009
422
14
Was that mentioned? I did have a look at HP's site. Is yours the 6P?

They do indeed claim SL drivers come with the OS.

You've absolutely confirmed the printer to be the cause of your Mac's sleep disturbances so I suppose you could either just leave it disconnected while sleeping or contact HP for support.
Thanks.

Yes, with the printer cable plugged into the USB port going to the apple menu and selecting sleep looked like it would initially put the computer into sleep, but then it snapped right back on. The screen saver would kick in and based on the power settings it would sleep, but then come on intermittently during the day/night.

Unplugged the cable to the printer (even when it's off) and viola. iMac goes right to sleep and stays asleep.

Strange for sure.

-- M