Turn On PC remotely?

Thanks Bob. If you have time, would you elaborate on these 'features?' I told my boss the only way to turn on a ATX machine is to do it on the "DC" side of the supply, with the cables to the motherboard. Is the "auto turn on" a setting in the bios or something? Half the PCs around here don't even have switches on the PS, only the one on the tower, connected to the MB.

I am not at all familiar with an ATX machine that will come on when power is restored, but then I don't get to see all the PCs that are out there, so I am sure you see things that I am uninformed about.

Do things like the internal modem get power from the supply, even tho the motherboard has not turned it on? I guess that might be the key, if I can find a way to confirm that the modem would be in a sleep mode. I don't have a lot of PCs to look at, let alone up to date machines, so anything you can toss out there would be a big help.

Thanks a lot,

John

Three possibilties;

1. Check the BIOS setup for some power setting option that causes the motherboard to control the ATX PS in such a way that it behaves like an AT PS of old. If it's there you should be able to figure it out and test it.
2. Wake on Ring (WOR). Allows the computer to power on from off or wake from standby/hibernate via a MODEM when the phone rings. Very popular for FAX use. Search Google.
3. Wake On LAN (WOL). As above but using NIC and "magic packet" instead of MODEM. Search Google on >WOL subnet

This BIOS power menu option is called "Restore on AC power loss" on ASUS motherboards. If set to "Power On" then the computer will "power on" after AC power loss is restored. Look for something similar in your motherboard's BIOS.

Many modern PCs will restart themselves after a power outage. Also, it is possible with many modems to start up the PC when the phone rings. Check your BIOS settings.

--
Regards,
  Bob Monsen

Intuition is the undoubting conception of a pure and attentive mind, which 
arises from the light of reason alone, and is more certain than deduction.
- Descartes

Many thanks to everyone for the input. I appreciate the help very much.

I don't wish to appear to not believe folks, so please don't misconstrue :-) as I went digging even further into the ATX PS specs, and so those who have machines that are working are encouraged to tell me I read it wrong

It seems that most, maybe not all, but most of the WOL stuff only work if the PC was shutdown from Windows, not from having its power pulled from the wall. Near as I can tell, when windows shuts down the PS, if it is properly configured to wake up, then it tells the PS, which keeps a single power pin on the MB alive for the properly configured NIC to stay awake, waiting for the proper packet to arrive and tell it to wake up the PS. Basically, under these conditions, the PC is off, but the power supply is still on. Can it get into this condition if the input to the supply is cycled off and on, as in a power failure?

I think that as I read ATX v2.01 that a pin is now always live, so that a NIC or a modem can be accessed no matter how the PC was shut off, but I am not sure I have interpreted that spec correctly. We also don't have any ATX 2.01 PS's for me to test with, so I am hoping someone may offer a clue.

Now, I did not ask the question to get folks to answer so I could argue :-) I just asked, and then spent the day digging through the docs and now am a bit confused and want to learn how this works.

Those who use the wake up feature, does it work if you pull the plug, and simulate a power loss, or only when you properly shut down windows? I am inclined to think the latter is the only thing that works, in that if the power supply is cut off, the BIOS really has nothing more to say until the PC boots again.

Can't say it enough, and will repeat it out of paranoia I didn't bring it up to argue it, I am just not able to try a dozen computers to see how each one really works, so I am throwing out what I know, to compare to those who are wiser, and may well be using this feature successfully. Several folks said that they are, but does that include a power loss at the input to a supply, as well as a windows shutdown?

Thanks a lot for the help,

Mark

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@g49g2000cwa.googlegroups.com:

ATX supplies and more recent pc motherboards (last 10 years or so) allow a number of power on options. Firstly unlike an AT machine ATX pc's are always on if there's power on the mains side of the power supply. Even when they are turned 'off' by the front switch the pc still has power to the MB. Bios settings usually allows a 'wake on' function where if a specific keyboard sequence or mouse key is hit the pc will power up. Similarly integrated peripherals like lan/nic card or modem often allow a wake up on a wake up packet to the lan card or a dial in to the modem. seperate lan cards and modem cards often have that feature too. Do a google on 'wake on lan' as an example.

Bios will usually also allow you to set an option in case of power loss. Ie, power back up or not. Some Bios will also allow you to set a boot up time too.

Haven't done it but there are some software utilities to do the same, that is specifiy a start up time and the pc will boot. I think Windows has something similar at some point / version/patch etc but again I've never used it.

Many know of the ability, but don't really understand how it is accomplished. You will find no such ability in the ATX power supply specification because the function does not exist inside a power supply.

Power supply is only one part of a power supply 'system'. The power supply provides a dedicated voltage (+5VSB) to a power supply controller located on motherboard. The power supply controller determines how, when, and if power supply will turn on. The BIOS has options to change how that power supply controller operates. IOW options to power up a supply by external events is defined by the power supply controller - unique to that motherboard design and setup in CMOS setting - what some call the BIOS.

This power supply c> Many thanks to everyone for the input. I appreciate the help very much.

Just to add a bit, the ATX power supply has a +5V output that is always on, regardless of whether the #PS_ON pin is low or not. This is called the

+5 VSB output. It is usually limited to 1A or less. It is pin 9 on a standard 20 pin molex power connector. It is used to power systems that can wake the computer, like Wake On LAN, softmodem, intrusion detection systems, and that sort of thing.

In addition, bios usually have settings for restart after power loss. This is critical for server systems, and doesn't depend on the OS, so it is probably on your systems unless they are more than 5 years old. Just boot into the bios (usually by holding delete, F1, or something like that) and look around.

--
Regards,
  Bob Monsen

A great truth is a truth whose opposite is also a great truth.
- Niels Bohr

Use a modem, and configure the PC for "wake on ring"

There should be a bios option to make it wake on power being restored.

Or you could short the green wire on the power connector to one of the black wires, that should work too

Bye. Jasen

Depends on which Windows you're using, the motherboard BIOS and the NIC drivers.

In some machines I use the power option AUTO POWER ON ( in BIOS) is set to Everyday 7 AM, then it comes on when I turn the mains power on and stays on until the power goes off and comes on again if there is a power switchoff and on. Seems just what you are asking for.

One of these machines is in an locked cupboard and is used to control all the functions of a 1925 Wurlitzer Theatre organ without any operator intervention at the computer keyboard.

--
John G

Wot\'s Your Real Problem?

Just lots of thanks for those who took the time to offer answers and ideas for my question.

Between the wisdom of you folks, and some digging on the net, I have a handle on it.

Much obliged,

Mark