iMac will not remain in sleep

[Jasper7]

My OS is 11.2.3

Sleep will only function for about 30 seconds and then the screen lights up again. In one isolated instance after the screen had lit up again and remained lit up for some time it suddenly went dark, but only for about 30 seconds before lighting up again.

I have checked Apple's help page but nothing I am able to do fixes the problem.

 

[Cory Cooper]

Hello,

Try going to  > System Preferences... > Energy Saver and uncheck Wake for network access.

See if that helps.

C

 

[Jasper7]

Hello,

Try going to  > System Preferences... > Energy Saver and uncheck Wake for network access.

See if that helps.

C

No, it hasn't helped I'm afraid.

 

[Cory Cooper]

OK, thanks.

You could try: How to reset the SMC of your Mac

C

 

[OC Joe]

My OS is 11.2.3

Sleep will only function for about 30 seconds and then the screen lights up again. In one isolated instance after the screen had lit up again and remained lit up for some time it suddenly went dark, but only for about 30 seconds before lighting up again.

I have checked Apple's help page but nothing I am able to do fixes the problem.

I had the same problem and this resolved the issue completely: When your curser is over the "Sleep" icon, at the same instant you click it you completely remove your hand from the mouse. I found that if there is the slightest hand movement on the mouse after the icon is clicked, the Mac will go off then come back on but this method, for me, works every time and it never comes back on. I have no idea if that is true for all Macs but I assume it is...?

 

[ColinBird]

I've seen the same behaviour very occasionally with Mojave (10.14). I usually leave the iMac to do its own thing, which means the swirling colours screen saver. When, after next using the iMac, I ask it to sleep it behaves. Annoying behaviour, agreed, but only intermittently so. Restart fixes it too, but that is a more drastic solution.