Spooky

D-Dan · May 24, 2011, 12:35:10

My computer is in my bedroom, which is handy for watching late night movies in bed, and last night I did so before shutting the PC down and settling in to sleep.

At 4:33 this morning, I was awakened by the startup sound of my computer, and when I looked over it was just completing bootup. No scheduled wake up in the BIOS, no scheduled events, and nothing in the logs (Debian based OS).

This is a rather worrying turn of events in my computer usage.

Steve

Rik · May 24, 2011, 12:54:25

A wake up call from the network?

JB · May 24, 2011, 12:59:00

Is the BIOS set to boot the machine when power is restored? If it is and there was a short power cut, that would cause the effect.

Rik · May 24, 2011, 12:59:41

Good thinking, JB.

Gary · May 24, 2011, 13:01:09

My Mac boots up if the UPS gets a kick when the power goes out or there is a voltage fluctuation, are you hooked up to one?

Simon · May 24, 2011, 13:05:30

Or, it could be a ghost...

Gary · May 24, 2011, 13:06:57

Quote from: Simon on May 24, 2011, 13:05:30
Or, it could be a ghost...

Glenn · May 24, 2011, 13:07:50

To many sprits in the evening?

cavillas · May 24, 2011, 13:39:47

Perhaps it was just feeling lonely and unused.

D-Dan · May 24, 2011, 14:26:40

No UPS, resume after power outage is set to soft-off, all wake up events on hardware are disabled and if it feels lonely and unused I'm not sure what more I can do when I'm sat at it for 14 hours per day.

Someone has suggested a recent linux update may have messed up some power management and to set BIOS suspend to S1 rather than S3, so I've done that and I guess I'll see in the morning.

If it turns out to be a ghost they will get a shock because I'm setting a boot password in BIOS now

Ahh - the plot thickens. It seems that the TV was not in a fully shutdown state either - wonder if there was a power surge enough to kick them in to life

Gary · May 24, 2011, 15:52:27

Quote from: D-Dan on May 24, 2011, 14:26:40
No UPS, resume after power outage is set to soft-off, all wake up events on hardware are disabled and if it feels lonely and unused I'm not sure what more I can do when I'm sat at it for 14 hours per day.

Someone has suggested a recent linux update may have messed up some power management and to set BIOS suspend to S1 rather than S3, so I've done that and I guess I'll see in the morning.

If it turns out to be a ghost they will get a shock because I'm setting a boot password in BIOS now

Ahh - the plot thickens. It seems that the TV was not in a fully shutdown state either - wonder if there was a power surge enough to kick them in to life

Normally power surges damage not turn on, well I would have thought that with a TV, are you using sure suppressors and are they working properly, and/or do you have cats

JB · May 24, 2011, 16:57:32

Quote from: Gary on May 24, 2011, 15:52:27
Normally power surges damage not turn on

My money would be on a very short power outage, less than one second.

Might be worth asking your neighbours if they experienced anything similar with any teccy gear.

pctech · May 24, 2011, 17:41:14

My money's on a ghost.

Rik · May 24, 2011, 17:43:59

In which race, Mitch?

D-Dan · May 24, 2011, 20:23:03

Quote
Normally power surges damage not turn on, well I would have thought that with a TV, are you using sure suppressors and are they working properly, and/or do you have cats

Normally I would agree. However, the TV is plugged in to one of those standby saver sockets, so a small surge may have been enough to trip that and to kick the PC into life. I don't mean a lightning strike here, just a small increase. No cats, dogs or any other pets to worry about, and I was the only one in the house.

Quote
My money would be on a very short power outage, less than one second.

That's my 2nd theory. Any power outage is usually given away by the clock on the cooker resetting, which it hadn't. However, if it was only for a fraction of a second the clock may not have registered it and kept going on residual charge.

Whatever the explanation, it doesn't seem to have done any harm

pctech · May 24, 2011, 21:45:02

Quote from: Rik on May 24, 2011, 17:43:59
In which race, Mitch?

Technical Ben · May 25, 2011, 10:45:11

Quote from: D-Dan on May 24, 2011, 12:35:10
My computer is in my bedroom, which is handy for watching late night movies in bed, and last night I did so before shutting the PC down and settling in to sleep.

...

I think I remember my PC doing this once. The only explanation I can think of is "keyboard for power up" as a call in the bios. I always turn my pc on from hibernate with a keyboard space bar press. However, if a battery, pen or cat falls onto the keyboard, the pc will turn on. So perhaps it was just something triggering the power? Even a loose wire in the power button could have a tiny bit of contact, and just get pressed together at a certain time.

D-Dan · May 25, 2011, 11:08:31

I don't think that's it. Oddly, at the time I know for a fact that power on from KB/Mouse were both disabled in BIOS (I know this because I re-enabled them yesterday after making some progress on a hibernate/suspend problem I was having). Having said that, even when they are enabled they don't work, so it's highly unlikely.

Equally, there is no loose connection on the power button - it needs a solid press to power up. In any event, the chassis has a front door which obscures the power button and so prevents accidental contact :/

Gary · May 25, 2011, 11:09:41

Dont those saver sockets operate via a house hold remote as well? I know some do so you can turn off the TV and then the standby saver and all attached to one side or something like that, could you have crashed out with a remote in hand?

D-Dan · May 25, 2011, 11:19:43

There isn't a separate remote control unit, though it does work in the manner you describe, in that any appliances plugged in to the extension on the power save side (there are two permanent sockets and four powersave sockets) are powered off with the TV. However, the TV is in a separate room and doesn't share the power saver with the PC (I watch TV on the PC, not the TV). There is no such power saver on the PC socket.

Technical Ben · May 25, 2011, 13:31:10

I know it seems unlikely, but the example of the button is a common one. For example, the buttons are mechanical. It does not take much to bend, break or wear out a connection, or plastic mechanism. So, they can become loose, or just stuck. The next day, you press the button, and it becomes unstuck. A tiny vibration could have been enough to knock the button into place, if it was resting just off the connections.

It's only one example, but it's one of many mechanical, and explainable situations. Another common one I have, is loose plug sockets. They can get tangled in the wires, pulled by moving tables/chairs or just mice/keyboard cables. So, they break the connection, then it's fine. Although, you ruled this one out as the bios is set so not wake up. However, I've not know a bios to work 100% as it claims to, especially when power options are involved.

[edit]
An example of the ways a bios can give different setups then the one you selected is a system crash. If your system did not turn off properly at night (IE power cut) the bios can mistake this to mean a chipset failure. So, instead of staying off, when the power came back on, it went into "default" or "safety" mode. In a default or safety mode, all the settings are reset to normal power settings (wake up from powercut state) and default CPU/Chipset settings. This is to protect it from wrong setting given by the user. I suppose, the setting of wake up, is not the best one to have as a default. It does however seem to be the common one selected by motherboard manufacturers.

My PC did this when I was checking it's overclocking settings. It kept thinking my power down, was a crash. Each time I turned the PC off, it reset the bios into safety mode to recover from the crash. However, there was no crash! After a reset, it went back to my user settings. So when I went to check the bios, the settings were alway as I left them. Howevr, it never used the settings I left.

Thankfully, a new bios update corrected the error, and now it knows when I turn it off, it's turning off properly. Then it turns on, with the same settings I gave it.

D-Dan · May 25, 2011, 13:48:02

Whilst you make valid points regarding both possible loose connections and a loose power socket etc, it wouldn't explain the apparent concurrent failure of both my PC and the TV, located in separate rooms and powered from different sockets.

I'm quite happy to chalk this up to Casper being curious and then moving on

Technical Ben · May 25, 2011, 14:06:57

Power failure would cause both:
1) TV. When the remote plug looses power it looses the details for the TV that it uses to detect "on" and "off". In the morning, the TV is in the wrong state (standby, instead of completely off).
2) The bios on the PC detected a powersurge/cut. Instead of chalking this off as "power down" it thinks it was a "bios crash" and goes into safety mode. When the power comes back on, or there is a second powersurge, it turns on. Later, it is no longer in safety mode, so the bios looks normal.

Easy as pie.