My iMac is taking ages to go to sleep

Some users put their computer to sleep, while others shut it down. Some users aren't aware of the difference, but it's a really important difference.

I'll take you at your word. You probably sleep your iMac by pressing Cmd-Option-Eject at the same time; your machine should sleep in one or two seconds, and wake up just as quickly.

If, however, you shut down your computer every time, it will take longer to shut down; the time varies by the size of your HD and the amount of RAM that's installed. Usually, between five and twenty seconds. If your RAM is maxxed out, or you don't have much HD space left, that could be the explanation.

Post with your results!

Ah, 16GB RAM - that could be the source of the problem.

Adding RAM is a great idea, especially with RAM-hungry applications, but it can really slow down sleep. Read this thread on commands to reclaim the sleep image:

http://forums.macrumors.com/showthread.php?t=1416347

Or, you could insert your old 8gb RAM module (if you still have it), and see if that improves things.

Post with your results!

Sound like either a running process or sharing preference.

Have a look at > Mac OS X: Why your Mac might not sleep or stay in sleep mode

I'm not sure exactly which Sharing Service or Apple Device is using "ApplePushServiceTask" because for privacy all my Sharing Services are off unless one is needed.

Go to Apple > System Preferences > Sharing and try turning off your Sharing Services one at a time, then test the iMac to see which one is preventing it from sleeping.

If you find that you need that Sharing Service on for whatever reason(s), then only the Display and not the iMac can sleep.

OK next try ejecting and disconnecting your Seagate Storage Drive.

It might also help us to know if you are using the Seagate for TM Backups, Media storage and playback or using Seagates Backup?

For example: Are your iTunes Libraries stored on the drive and if so, is iTunes open and using the Library? If so, then try quitting iTunes and see if that will allow the computer to sleep. This may also be the case with other open App's like iPhoto, if your Libraries are stored and in use on the external drive.

OK next try changing the batteries in your Apple wireless devices and then start removing other USB devices one at a time and see if it will sleep.

Sorry I'm not good at reading the Logs and after re-reviewing them, I now see a "Wake due to EHC2/HID Activity: Using AC"

On that note, see > Something keeps waking up my Mac, how do I find out what it is?

Me too..

Through all of this, have you tried...?

Resetting the SMC > Resetting the System Management Controller

1. Shut down the computer.

2. Unplug the computer's power cord.

3. Wait fifteen seconds.

4. Attach the computer's power cord.

5. Wait five seconds, then press the power button to turn on the computer.

and then the NVRAM / PRAM > About NVRAM and PRAM

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Turn on the computer.

4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.

6. Release the keys.

Hi!

Just move to trash these files:

Library/Application Support/Seagate/Seagate Storage Gauge

Library/LaunchAgents/com.seagate.SeagateStorageGauge.plist

And then log out or restart your computer.