Linux scheduled tasks

[#1]

Is there any task schedulnig in ubuntu 11.04? I have been having problems with my computer booting up on its own. Checked the bios and all waking up off hardware has been disabled, just wondering if any software could be doing it or possibly a faulty power switch.

[#2]

Can a computer boot itself up - without hardware intervention?

[#3]

I'm not sure m8 doesn't sound feasible, I just wondered if maybe in ubuntu when I power down it actually means totally off and not in some sort of hibernation state that can be restarted  Other than that the power button on the front of the case is just a simple push in for on, I can't see how this button could fail, I would have thought if it did it would fail in the off position.
Last night PC powered up on its own so I shut it down and knocked off the power by the main switch on the back of the pc but when I tried to switch it on again It loaded the bios defaults and had to go through a hard disc check if that's any clue. I know on windows I can go to any ethernet cards and disable the allow this device to wake things up in computer hardware. Not sure if these settings are available in ubuntu.

[#4]

[quote=AverageWhiteBloke]I tried to switch it on again It loaded the bios defaults
How old is this PC ?
I am wondering from that symptom, whether the lithium battery that maintains the BIOS memory is in need of replacement ?.
If the battery is dead, then there is a risk of the BIOS settings being lost when the power supply is switched off.
If the PC is older than say 3 or 4 years, it would be worth replacing the battery anyway (for peace of mind).
The battery is usually a CR2032 or CR2016, which should cost less than a pound.
In addition, if the BIOS memory can't be relied on, then the settings for the wakeup hardware might become randomly configured.

[#5]

Quote

If the battery is dead, then there is a risk of the BIOS settings being lost when the power supply is switched off.

Yeah a definite possibilty hence the bios settings going when I totally killed the power, even after a few rebuilds the mboard is about seven year old

[#6]

Have you changed/upgraded any hardware recently ?, as I have seen intermittent BIOS memory loss on system boot-up when the hardware is all running up and being probed by Ubuntu, as this is a brief moment of maximum power supply loading.  If that maximum initial load exceeds the power supply rating, then some BIOSes take recovery action and load either default, or lower stress values, to try and allow the system to at least boot to the BIOS screens.  One of my PCs (under these conditions) gives an alarming message that the wrong CPU is fitted ! - but it has actually wound down the CPU FSB speed and then discovers then CPU ID does not match the BIOS settings 

[#7]

No hardware changed recently, this is my main system in the house for the family to use and as a server for my ps3. I haven't changed anything on it for years. I put Ubuntu on when the LTS came out and it just runs seamless other than started this booting up on its own. I've noticed that it shuts down very quick compared to windows i have on other systems near on instantly. Just thought with it shutting down that fast possibly it wasn't proper shutting down just sort of hibernating. Clutching at straws really 
I'll give the battery a shot first and take it from there. As mentioned there was no reason for the bios to go back too defaults after the power supply was cut. Hopefully that may solve it.

[#8]

Recent Ubuntu releases do shutdown reliably in a matter of a few seconds.
Good luck with the battery, it is probably worth using the motherboard link to reset  the BIOS after you have swapped to the new battery - while you have the case open !.

[#9]

Cheers I will do that. I might even have another crack at installing the hard drive that melted my head last time while the box is open