The condition has continued. After selecting sleep and putting the computer to sleep, it will start up again at will without any interaction. This occurs when disconnected from the internet.
There have been no changes in configuration or installation of new software.
I thought this awakening of the computer could be a character of a virus program or Unix maintenance programs. But this didn't occur before and no matter now many times I put the computer to sleep it continually awakes. All I can assume is some component in the system has changed by itself.
It is not really an issue as such, but the problem is that when the computer awakes by itself the fan doesn't run (usually the fan is running when the computer is warm - so the fan is still functioning) so the computer becomes like a hotplate, which could lead to damage of the motherboard. I usually find the computer really hot after being out or in the morning.
Any ideas as to what is causing these self starts would be helpful.
You could try resetting the SMC
though that is more to do with a runaway fan, where is your case there seems to be a disconnect between the fan and the CPU, Still, easy enough to do that reset.
Why it won't stay asleep? Even if off the internet, what else is connected to it that could be interacting with it?
Try disconnecting any other stuff ( for trouble shooting purposes) to see if that makes a difference.
Thanks for you input roam
Will try the reset, as there is nothing else connected to the computer to cause this. It is quite a mystery that I haven't experienced before.
When I am home I spend a lot of time putting the computer back in sleep mode, to avoid overheating.
As I mentioned, the fan works while the computer is in normal use, but doesn't work when the computer awakes by itself. All in all strange indeed.
I have been having trouble with Safari constantly reloading if more than one page was open. As I test I started to close Safari after use or before putting the computer to sleep. It seems that if Safari is not running the computer doesn't awake by itself; just 12 hours to now but seems somehow that Safari was the cause.
This seems the solution. Now I close Safari every time before I put the computer to sleep and the auto wake-up doesn't happen anymore.
As for Safari, the solution seems to be what you suggested, the only issue is I log into many sites and having to type in the passwords everytime as well as loose my extensions (WOT, AdBlock, Cookie management) could be a drag.
For the moment I am using the open tab and trying to keep to one window in Safari. It would be great if I could find some .plist or whatever to delete.
Thank you so much for the support, much appreciated.
You are welcome.
Regarding your browser usage, Firefox is widely used by a lot of Apple users, you don't have to use Safari.
Both Firefox and Safari can remember usernames and passwords(1) to prevent re-entering them each time. Firefox has extensions ability as well, in fact they are an old hand in that respect, and Adblock and Noscript are available.
I use both Safari and Firefox, for different purposes.
For internet banking and the like I use only Safari, manually enter username data, do what I have to, then leave the site and close Safari.
For all else I use Firefox.
(1) some financial institutions intentionally block the retention of username and password data, as an added layer of security. I think it is good practice to enter this data manually.
Yes, thank you for the thought. Actually, I also have both Firefox and Safari installed. But I always found Safari addictive or habitual. With the resent issues that Safari has thrust upon me I downloaded Version 12 of Opera this morning, and this seems to be quite a good substitute for Safari. I always had Opera installed but only used to check rendering of my website, I had used version 9 for that, the newer version seems much better.
I really find Safari's unstable states recently quite amazing and wonder what is going on with the team responsible for Safari at Apple. Safari just freezes when certain data tracking companies' cookies are downloaded, so I have been spending a lot of time deleting these. Well looking forward to an update of Safari.
Hi Roam, Just posted in the Safari thread; I downloaded the latest WebKit build last night and now Safari is all right and the auto awake issue has also gone away, so the issues must have all been related to Safari. Thank you so much for your ideas and support, it helped a lot. Got to quite like Opera over the last day or so too.