My PC wakes up from Sleep Mode when I put the room lights off!
inakic
Posts: 10
Hi everybody.
I have an odd problem with my new PC.
I set it to Sleep Mode (in windows). It enters Sleep Mode as expected. No noise from the unit, just the power led blinking.
However, when I leave the room and put the lights off, the system wakes up!
FYI, the lights in the room are hallogen lamps, which I have heard produce tons of EMI noise, but I wonder, is it that much as to be able to awake the computer?
I have the PC power supply connected to a UPS. I have tried to plug the PC to another socket.
I have tried removing every cable, leaving alone the power cable, and it keeps doing the same odd thing.
The PC case is a low noise Fractal Design R3. The power supply is a Corsair 650W.
The motherboard is an ASUS P6T Deluxe V2 with Core i7 CPU.
Has anyone any clue about what is happenning here? :-(
inakic.
I have an odd problem with my new PC.
I set it to Sleep Mode (in windows). It enters Sleep Mode as expected. No noise from the unit, just the power led blinking.
However, when I leave the room and put the lights off, the system wakes up!
FYI, the lights in the room are hallogen lamps, which I have heard produce tons of EMI noise, but I wonder, is it that much as to be able to awake the computer?
I have the PC power supply connected to a UPS. I have tried to plug the PC to another socket.
I have tried removing every cable, leaving alone the power cable, and it keeps doing the same odd thing.
The PC case is a low noise Fractal Design R3. The power supply is a Corsair 650W.
The motherboard is an ASUS P6T Deluxe V2 with Core i7 CPU.
Has anyone any clue about what is happenning here? :-(
inakic.
Comments
Halogens are not especially EMI prone - but if they are fairly high current then that will explain a power transient (the switch-on from cold is a much larger transient as the current is much more). Fluorescent strip lights are very EMI prone, perhaps thats what you were thinking of?
I'd say this one is pretty likely. When your computer is asleep and the lights are on, does moving the mouse wake the computer up? If so, I'd guess that Duane is on to something...
Actually I think this is likely a "Feature".
I have a nice Toshiba laptop which exhibits this same thing.
I put it to sleep and power down my nice laser wireless mouse.
My laptop will wake up if:
1. I open the lid.
2. I turn on the mouse.
3. (The interesting method) If I pass a finger over the power on LED it turns on.
Remember, LEDs act both as light emitters and light sensors.
The "Feature" circuitry watches the voltage generated by the LED when sleeping.
When it sees a rapid change of voltage it signals power on mode.
Ok, this usually happens when opening the cover.
But a quick turning off of the light will also do it.
Try turning it on by simply passing a finger over the power on LED. I bet it will start up.
OK, The normal way of putting it to sleep is closing the cover.
Also don't forget that moving the mouse can also start it up from sleep mode.
Laptops are pretty immune to noise so I would not think RF noise in the room would cause unless it is outrageously high.
Duane J
If it's not that I recommend an immediate exorcism, go toward the light I think.
Un-plug the mouse and set her to sleep to see if this fixes the problem. That should give you a better idea of whats causing the issue at the least.
You might have to put the mouse away to avoid triggering. Frankly, I don't use SLEEP mode as it drives me crazy and wastes electricity. If you don't want it, can you turn it off?
I need to look into this in W7 as my Toshiba laptop shuts down in Linux when I close the lid, but goes into SLEEP mode in W7. I forget about it and battery goes dead. (That is why I dislike SLEEP mode). Shutting the monitor to save power is useful when you are processing a long run of something, but SLEEP is a bit too much for me.
I once used a laser and a photo-transistor inside a parabolic dish to make a laser switch. It was activated by sticking a finger in the parabolic dish (I recycled it out of a Maglight) and it fit the front of my PC perfectly.
That will eliminate the 'dark' effect.
I had a sensitive keyboard in the past (some 20+ years ago) that behaved erratically and halted the pc every time you 'injected' a bit of static into it.
If not,
Shield the power button. Can you get some braided shield cable and fasten one end to ground? Or maybe wrap the wire in a ferrite toroid a few times to trap the transient. Maybe do both.
OR
Change the Power ON options in the BIOS configuration to 'none'.
I will download the motherboard documentation and take a look at what might be a problem in the BIOS configuration. Then I will get back to you.
Do you have a backlit keyboard that might be sensing light?
I have the same problem. If your problem is solved,please tell me how thank you
Unless the PSU that runs the lamp is SMPS too . then its any ones guess .......
Peter..
If the noise is RF there's not as much you can do about it, unless maybe upgrade the case or try a different network card. But if it's noise coming through the power line, this suggests you should be using a good surge protector. The surge protector may not stop the false triggering, but your PC is getting some dirty power.
I remember an old Dell All In One I had, it had a motion and light sensor on it that would wake the computer too.
If it happens with just the AC cord, another thing to try is shining light on the PC using a bright flashlight instead of the room lights. You should be able to pinpoint the location of the sensor with a flashlight's narrow beam.
I don't think noise on the AC could penetrate all the way down to the standby DC circuits, but that's just a guess. I've deployed computers in the worst imaginable environments, often not even earth grounded (in the USMC). I've never seen noisy power do anything but artifact CRT displays, or LCD that don't have ferrite cores around the cables.
Most BIOS and operating systems can selectively adjust what can wake the computer. It would be real easy to disable everything, then add things one at a time if someone didn't want to unplug everything.