Computer restarting on its own after shutdown

[genegold]

Starting about a week ago, my computer has begun to restart sometimes about two to three seconds after it has seemingly shut down (via Win 8.1 shutdown). I suppose it could be a start switch going bad, although in the three years I've had this Cooler Master case I've only recently begun starting manually, vs. powering from a console. Before I write Cooler Master about a replacement, if feasible, are there any other possibilities? Thanks,

[parsec]

Re: Computer restarting on its own after shutdown

I don't see BIOS (UEFI) U1h on your board's download page, so don't know what its features are, all I see is U1L. I assume U1H is a beta UEFI from @BIOS?

Did you remove the Gigabyte utilities that are not compatible with the UEFI BIOS?

Other mobo manufactures I've seen have UEFI/BIOS updates that include modification for "Windows 8 shutdown behavior", not sure if Gigabyte has anything similar.

I would look into the power switch, I'm sure the part that contains the power button could be replaced.

For a test, you could remove the cables from the power switch to the boards system header. Then start the PC by momentarily shorting the two pins that the power switch cables were connected to. Later shutdown the PC via Windows, and see if it remains off.

What do you mean exactly when you say, "I've only recently begun starting manually, vs. powering from a console"? Starting the PC via the keyboard or mouse?

[genegold]

Re: Computer restarting on its own after shutdown

Thanks for the ideas. I woke up this morning thinking it's unlikely to be the switch, since after cutting off it must be getting an electrical signal from somewhere. For BIOS instructions, you have to see the Z77-UD3H board manual. I haven't changed BIOS settings for awhile, but will have to check that. I'm wondering if the the power supply isn't the culprit, with some kind of signal being re-sent. Be interested to find out more about Win 8 shutdown behavior, if there's anything special. What I meant by powering from console is that up until recently I had the computer plugged into a console and the BIOS set to start with power. Since adding a good audio system and upgrading the wall outlet quality, the computer is plugged directly into the wall. That means manual start from the computer start button. Since late November.

[boondocks]

Re: Computer restarting on its own after shutdown

You have your signature showing a Z68 board, and you are talking about a Z77 board....not that it likely makes any difference.
I doubt the manual switch is bad, anything's possible but I tend to doubt the switch. The symptoms of restarting right after shutdown seem more BIOS or OS related to me.

Changed any BIOS settings lately? Installed any utilities?
Have you tried reflashing the BIOS and loading optimized defaults?

[genegold]

Re: Computer restarting on its own after shutdown

It's interesting, I normally hold off posting a second place, but this time I didn't and have gotten very different thoughts/suggestions from each. Both are worth trying: 1) reflash the BIOS and 2) disconnect the cable modem before shutdown to test if it's sending a WOL signal. I also contacted Kingwin, the PSU maker, and they are looking into whether or not it could be their unit. As for boards, Gigabyte didn't update the Z68 manual when UEFI became common, so the pertinent info has to be drawn from their Z77's manual.

[absic]

Re: Computer restarting on its own after shutdown

Hi there,

noticed from your spec's that you're using a Dell monitor that has USB ports. Have you connected this to the PC via USB? If yes, try removing the USB cable as I found with my Dell monitor the same thing happening. Only stopped rebooting once I had disconnected the USB link.

[genegold]

Re: Computer restarting on its own after shutdown

DVI not USB. Note that I put this system together close to two years ago and this problem only developed in the past seven days or so.

[- wardog -]

Re: Computer restarting on its own after shutdown

Hi there,

noticed from your spec's that you're using a Dell monitor that has USB ports. Have you connected this to the PC via USB? If yes, try removing the USB cable as I found with my Dell monitor the same thing happening. Only stopped rebooting once I had disconnected the USB link.

DVI not USB.

I'm thinking absic was inferring if you have the monitors built-in USB hub connected back to the computer to disconnect it and see if your rebooting stops.

[genegold]

Re: Computer restarting on its own after shutdown

Thanks, but I don't use the monitor's USB hub. Not even sure I ever got them working, though there's no need.

[- wardog -]

Re: Computer restarting on its own after shutdown

I give. Your PSU, All I can seemingly find are your posts here and elsewhere when Googling "Kingwin LWP-550".

Maybe LZG-550 or LZP-550 instead?

[genegold]

Re: Computer restarting on its own after shutdown

LZP-550. Thanks for spotting the typo! Welcome to www.Kingwin.com: Power Supplies - Lazer Platinum Series 550w.

I used the PSU calculator before buying the Kingwin and then again a few months ago when I added an outboard audio system. The estimated max is 430w, and I was very conservative, including aging and adding devices. The Kingwin LZP-550 is an "80 Plus" and the Tweek Town reviewer found it tested a full 550W. He also said, "The LZP-550 is essentially a 650W Gold rated power supply that performs at Platinum efficiency when rated for 550W."

I just disconnected the cable modem before shutting down but the restart continued, so we can probably rule out the network module. One thing I didn't mention is that when the restart occurs, I immediately hold in the start button for several seconds and that kills it.

[genegold]

Re: Computer restarting on its own after shutdown

I posted this over on anandtech and got what seems to be the solution:

"One more thing you might try re the registry:

Location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

Double Click on "PowerdownAfterShutdown"

Then,
Change it to "0" if it is "1" OR
Change it to "1" if it is "0".

And hit Enter."
Computer reboots a few seconds after shutdown - AnandTech Forums

[- wardog -]

Re: Computer restarting on its own after shutdown

Interesting, and thanks.

You install any software or util recently that may have changed that? Backup sw maybe?

[genegold]

Re: Computer restarting on its own after shutdown

No. I used Windows backup and SyncBack Pro under Win 8, but only the latter under 8.1. I do have occasional freezes, apparently related to audio programs in conflict with each other and/or Windows 8 (started with a new dac and its driver last June). I assume the problem occurred because of one of those freezes, but don't really know. Upon rebooting, I immediately run Yamicsoft Windows 8 Mgr's repair module, which buys me a week or two until the next. If anything was wrong, that repair should have fixed it, but since it didn't maybe there was another cause.

[boondocks]

Re: Computer restarting on its own after shutdown

From what I read at Anandtech, you have other problems so it's hard to say definitively what causes what....I would think that value would be set in the registry normally to "power off", but maybe it's a Windows 8 thing.

Anyway glad you have some of it figured out!