iMac starting up during night from shut down state

[vermindo]

I have a 27" iMac with macOS Catalina 10.15.7 (19H114). When I go to bed I shut it down, wait and watch the screen go dark & the power go off (supposedly). For all appearances it seems to be powered off. In the morning, though, I find its screen saver on and it's at the login screen. There were no apps visibly running when I shut it down.

If it helps, it has a 2tb fusion drive, I run Bitdefender antivirus all the time, and use PrivateVPN. There's usually an SD card in the slot, and a USB drive sometimes attached to a connected USB strip. There's an Epson printer attached too, always in its sleep state.

Maybe you've seen this before, have a guess as to why? I'm not familiar with MacOS as much as Windows, so I'm still learning where to find which log files, etc. - could use a leg up. I've been searching everywhere but haven't found another example of this behavior so far.

 

[chscag]

Are you sure you're powering it off? It sounds like you've just put the machine in sleep mode. Putting the machine in hibernate mode or sleep allows it to wake up for processes such as network activity.

I have my 27" iMac attached to an UPS. If I want to power it down so that it does not wake up in the middle of the night, I switch the power of from the UPS to the iMac. Then there is no way it can turn on by itself.

I do that because of the sometimes bad thunderstorms we get here in Texas.

 

[wilberforce]

Check you haven't scheduled a start up time in Energy Saver (in System Preferences):

 

[chscag]

Good catch @wilberforce. I forgot all about the schedule options, having never used them.

 

[Fishrrman]

For about 33 years now, I've connected my Macs to power using a power strip with an on/off switch.

At night, I shut down the Mac, then reach down and flip off the power strip.

I've never once had a Mac start up in the middle of the night after doing this...

 

[vermindo]

For about 33 years now, I've connected my Macs to power using a power strip with an on/off switch.

At night, I shut down the Mac, then reach down and flip off the power strip.

I've never once had a Mac start up in the middle of the night after doing this...

That's great. Snarky unhelpful comments like this are why I generally avoid forums like these. That and 'RTFM' jabs.

 

[vermindo]

Check you haven't scheduled a start up time in Energy Saver (in System Preferences):

View attachment 1711231

Thank you, yes that was it. I'd forgotten that a long time ago I'd set that up.

 

[wilberforce]

That's great. Snarky unhelpful comments like this are why I generally avoid forums like these. That and 'RTFM' jabs.

I did not see Fishrrman's comment as snarky or unhelpful. It is unfortunate it struck you that way. It could be friendly, or it could be snarky, depending on the tone of voice and body language, which are impossible to discern via text. The wink emoji is usually intended to mean playfulness or joking.