Solved PC powers back on a few seconds after I "Shut down"

[Rave79x]

Hi,

Just finishing a new install of Windows 7 on an SSD, with a secondary standard hard drive.

A strange problem is occurring....when I press "Shut down" in Windows, after about 3-4 seconds, the PC powers back on again.

I can only prevent it doing this by cutting the power in that 3-4 second window.

This started happening just before I began the re-installation of Windows. I had been fiddling with overclock settings in the BIOS but then I cleared the CMOS by shorting the battery terminals. I assume this completed given that it prompted me to enter the date and time again.

Note that there are many threads on the Google relating to random power-downs and power up, but this occurs only after I click "Shut down".

I can only think this is a BIOS issue but I don't know which setting it could be. Apart from the boot priority I don't think I have changed any BIOS settings.

Should I try clearing the CMOS?

Anyone got any ideas here?

PC specs shown below...

Thanks in advance for any help.

 

[Schroff87]

When you cold boot does it power on by itself or do you have to press the button on your case?

 

[Rave79x]

When you cold boot does it power on by itself or do you have to press the button on your case?

Thanks for replying.

The mornings after its happened, I turn the power back on at the wall socket, then power on the PC using the button on the front.

 

[Schroff87]

There are usually settings like move mouse to power on computer etc, in the BIOS make sure they're disabled.

BTW just try leaving the computer alone for a minute at the time of cold boot before pressing the power button.

Also make sure the wiring in your PC is proper ... maybe something became a bit loose after SSD installation.

 

[BogdanH]

Check PSU

Hi,

Hi,
....when I press "Shut down" in Windows, after about 3-4 seconds, the PC powers back on again.

Question: after you choose "shut down", does complete PC actually shuts down (drives, vents,etc)?
If answer is yes: After very short periode (say, less than 3sec), PC just starts running again, as if you pressed power button?
If answer is yes: I don't know what else you have done (except connecting SSD), but there's a big chance, that your power supply unit causes this (more precise, it is +5VSB line from PSU). It doesn't necessary mean, +5VSB line it's totaly broken... can be, this line doesn't conform specification 100%, which is quite common with "no-name" units (at least, it happened to me). Btw. the problem (with +5VSB) is usually not voltage, but current!
See: http://www.formfactors.org/developer/specs/PSU_DG_rev_1_1.pdf

Bogdan

 

[carwiz]

Check to see if any "Wake on" settings are enabled in the BIOS. If they are, disable them. On Intel boards, these are in the Power section of the BIOS. The name and option may be similar to the following.

After Power Failure - Stay Off
Wake on LAN - Stay Off
Wake from S5 - Disable

 

[Britton30]

Next time you shut Down, turn your mouse upside down and see if it remains off. It sounds, at least, like you enter Sleep mode and mouse "creep" is waking it right away.

 

[carwiz]

Here's another place to check. It sets the function of the Power Button.

 

[Rave79x]

Lots of replies - thanks so much for your help. Will update soon.

 

[Rave79x]

Firstly, thanks again to everyone who replied.

BTW just try leaving the computer alone for a minute at the time of cold boot before pressing the power button.

Also make sure the wiring in your PC is proper ... maybe something became a bit loose after SSD installation.

I left it for 15 minutes with power connected and then turned it on but it made no difference.

I will check the wiring again.

There are usually settings like move mouse to power on computer etc, in the BIOS make sure they're disabled.

BTW just try leaving the computer alone for a minute at the time of cold boot before pressing the power button.

Also make sure the wiring in your PC is proper ... maybe something became a bit loose after SSD installation.

and...

Check to see if any "Wake on" settings are enabled in the BIOS. If they are, disable them. On Intel boards, these are in the Power section of the BIOS. The name and option may be similar to the following.

After Power Failure - Stay Off
Wake on LAN - Stay Off
Wake from S5 - Disable

BIOS settings as follows:

• Suspend mode: Set to "Auto" ("s1" and "s3" are available)
• Restore on AC power loss: Set to "Power off" ("Power on" and "Last state" are available
• Power on by: There are 5 different devices listed and each one is set to "Disabled".

Next time you shut Down, turn your mouse upside down and see if it remains off. It sounds, at least, like you enter Sleep mode and mouse "creep" is waking it right away.

I tried this also, but the PC still powered back on.

Question: after you choose "shut down", does complete PC actually shuts down (drives, vents,etc)?

All the fans do yes. It sounds just like it does when it powers off properly.

If answer is yes: After very short periode (say, less than 3sec), PC just starts running again, as if you pressed power button?

Yes.

If answer is yes: I don't know what else you have done (except connecting SSD), but there's a big chance, that your power supply unit causes this (more precise, it is +5VSB line from PSU). It doesn't necessary mean, +5VSB line it's totally broken... can be, this line doesn't conform specification 100%, which is quite common with "no-name" units (at least, it happened to me). Btw. the problem (with +5VSB) is usually not voltage, but current!
See: http://www.formfactors.org/developer/specs/PSU_DG_rev_1_1.pdf

Whilst Nesteq are not a well known brand, I think they make high quality PSUs. I bought it from quietpc.com/uk who I know test products carefully before supplying. I cost £90+VAT in 2007 and is silent, which I think is a good sign.

However, I'm running out of ideas here so I guess it could be the PSU. Unfortunately, I don't have a spare I can try.

Here's another place to check. It sets the function of the Power Button.

These are the power options I have set:
Guide Power Options and Diagnosis

So of the ideas suggested, its only the PSU (and perhaps checking internal cables again) that it could be I think.

Unless anyone can think of something else?

 

[carwiz]

Might be just a bad power switch or you have the Reset and Power switches reversed. Disconnet the front panel power switch and swap the reset switch (if you have one) to the Power on/off pins.

 

[Britton30]

Good idea Ken. That happened to me once and I did the switcheroo. In my case I accidently broke the power switch.

@Rave, you may also try putting the power switch leads on the reset header on the motherboard as well. Using reset is not a good idea anyway.

 

[carwiz]

Thanks, but it's only good if it works. I'm about tapped-out as far as any other ideas. I've heard of bad power switches before and it's easy to swap the switch leads by accident during a build or repair. Of course, I've never done that.

 

[debugged]

Whilst Nesteq are not a well known brand, I think they make high quality PSUs... However, I'm running out of ideas here so I guess it could be the PSU.

This is the PSU that caused the same problem on a system I worked on a while ago. It does run very quietly, but it has its quirks. One thing is to check you have the switch (the brass dial thingy) at the back of the PSU on the correct setting (I can't remember exactly what the options are, but it might be that simple to change settings - well, you can hope!)
It hurts to change a component you spent a lot of money on, but if it fixes a major annoyance, it's worth it in the end. A better silent PSU I would recommend - 400W Seasonic X-400FL Fanless Modular - brilliant.

 

[Atin90]

First, make your self a bootable floppy, if your PC has one. If not, boot to any bootable CD, DVD or USB you may have and then shut down. See if this will still give you problem
And if you still can find the cause, unplug everything from the PC, including the video, keyboard and mouse.
Do all the unplugging with the system running and use Power Button on the case to shut down. If this help, start plugging in one device at a time.
Lastly, since you were installing new SSD drives...try to boot with out this drive - unplug it, try to boot - errors are OK at this time and now shot down.
Other things that can cause this are loose cables inside PC, which sometimes can happen while you working inside the case.

 

[Rave79x]

Thanks again to everyone for the suggestions.

I've checked all the cables and they seem fine. I had already been using the SSD for a month when it happened and haven't been in case again, so I couldn't believe it was the reset/power leads being mixed up, or loose connections, but anyway, I checked them.

@debugged: I've contacted quietpc.com regarding the PSU as it seems far too much of a coincidence that you had the same problem with the PSU. I have an earlier model because mine does not have the brass dial on the back.

@Atin90: I'll try that soon. Thanks.

Thanks again all. Will update again.

 

[karlsnooks]

Rave,
Now don't you ever clear/reset the bios the way that you did. That is not exactly the best way and in case you are wondering I'm an elec. eng. with design experience.

Boot into your bios.

Choose to restore to the default settings.

Use the default settings and the default setting only.

 

[karlsnooks]

Rave,
When you get ready to shutdown, then:
WIN | type SHUTDOWN /S /T 10 | ENTER

WIN is the key with the wavy microsoft flag on top.

 

[Rave79x]

Rave,
Now don't you ever clear/reset the bios the way that you did. That is not exactly the best way and in case you are wondering I'm an elec. eng. with design experience.

Boot into your bios.

Choose to restore to the default settings.

Use the default settings and the default setting only.

Well, OK, I'll do it your way in future. Thanks.

(I just followed the instructions on:
Guide THE BASIC GUIDE & FAQ - ABC for OCZ SSD)

I'm not doubting you in anyway, but I've read the same method in a number of places. Its the first (and hopefully last) time I've cleared the CMOS.

This is the PSU that caused the same problem on a system I worked on a while ago. It does run very quietly, but it has its quirks. One thing is to check you have the switch (the brass dial thingy) at the back of the PSU on the correct setting (I can't remember exactly what the options are, but it might be that simple to change settings - well, you can hope!)

and

...but there's a big chance, that your power supply unit causes this (more precise, it is +5VSB line from PSU). It doesn't necessary mean, +5VSB line it's totaly broken... can be, this line doesn't conform specification 100%, which is quite common with "no-name" units (at least, it happened to me). Btw. the problem (with +5VSB) is usually not voltage, but current!
See: http://www.formfactors.org/developer/specs/PSU_DG_rev_1_1.pdf

The supplier has indeed confirmed its likely to be the PSU. What a shame. I don't think 4 years is a very good innings at all.

 

[karlsnooks]

There are many factors influencing the life of a power supply.

Mine have always outlasted the usefulness of the computer, but I do not overload them, I do not short anything, I make sure that they are kept well within their operating temp limits.

They are rather much like an automobile motor. With careful, gentle treatment and regular, frequent servicing they will outlast the usefulness of the auto.