Question PC will not power down

Oct 17, 2019
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Hello,

Apologies if this is the wrong sub-forum.

2 days ago, my PC randomly decided it wasn't going to power down. Windows 7 shuts down, then my monitor shows "No Signal" while my PC remains on, lights and fans still running. The only way to power it down is to flip the rear Power switch OFF. As soon as i flip it back to ON, the PC powers on immediately, but hangs in a 'sleep-like" state. From there, if I press the front power button once or a few times, BIOS will boot, then Windows boots up no problem. My PC works pretty much as normal aside from it not powering it down. I didn't install or do anything to the PC the day that this issue began. If anything, I installed a small spectrum analyzer program called "Spek" and Malwarebytes updated to a new version. But a system restore didn't have an effect. I did not do anything unusual that day. Pretty much just played some games and listened to music with Youtube and watched an episode on Netflix.

So far I have tried:

Clearing CMOS
Re-seating RAM
Unplugging and plugging HDDs and SSD back in
Shutting down with SSD disconnected (PC stays on)
Shutting down from Safe mode (PC stays on)
Cleaning dust
System Restore
Check driver updates
Check for unknown processes

My next step would be to try re-seating my graphics card. Will come back to this thread after I try that.

If anyone has an idea of what could be going on with my PC, feel free to chime in. So far, I've had this PC for 11 years and this is the only issue that I cannot seem to fix. Have not a darn clue what to do after I reseat my GPU.

Thanks!

System Specs:

Windows 7, 64-bit
8 GB RAM DDR2 800mhz
Nvidia Geforce 750 Ti, 2mb
600 W Rosewill Power Supply
Biostar T-series (forgot the exact model #) MOBO
250GB HDD, 750GB HDD, 1TB external HDD, 250GB SSD
 

Mrgr74

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Is your power switch on the front sticking? Look at where it plugs into your mobo and unplug the small jumper and swap it with your reset button. The reset button gets a LOT less use. While it's ultra rare for the switch itself to go bad, they can and do fail. If it fails in the (internal) on position, it'll constantly ground trying to stay on, even when shutting down. Keep in mind, I highly doubt this is the case with you, but it's worth a try. I had an identical sounding issue to what you are having on my dads PC a couple years back and when I replaced the power switch, which was a common push button type like 99% of the switches out there, it fixed his problem. That's why I asked you to try the reset button switch as it's the same as your power switch. (Unless you have a custom start-up-you-PC-hardware with flames coming out the sides as the NOS ignites and what have you. :) )
 
Oct 17, 2019
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See if you have fast start enabled, if so disable it and see if this helps. Also hold down shift key on keyboard while you use shut down in windows tab, see if it shuts down then.

I noticed this suggestion somewhere else, but I think that only Windows 10 has that feature. I am using Windows 7. There is an option in my BIOS that says "Quick Power On Self Test", which by default is set to "Enabled".

Is your power switch on the front sticking? Look at where it plugs into your mobo and unplug the small jumper and swap it with your reset button. The reset button gets a LOT less use. While it's ultra rare for the switch itself to go bad, they can and do fail. If it fails in the (internal) on position, it'll constantly ground trying to stay on, even when shutting down. Keep in mind, I highly doubt this is the case with you, but it's worth a try. I had an identical sounding issue to what you are having on my dads PC a couple years back and when I replaced the power switch, which was a common push button type like 99% of the switches out there, it fixed his problem. That's why I asked you to try the reset button switch as it's the same as your power switch. (Unless you have a custom start-up-you-PC-hardware with flames coming out the sides as the NOS ignites and what have you. :) )

Hey, I just tried swapping the connectors for the power switch and reset switch, however this did not solve the issue. I took another measure and disconnected every piece of hardware except the CPU/heatsink, and the PC would still power on as soon as I flipped the rear switch. I then tried re-seating some of the other connectors on the board. Nothing so far has solved the issue, I'm afraid.

Well, I guess a PC that doesn't power down is better than a PC that doesn't boot up.:sweatsmile:

Still open to suggestions if anyone has one.
 
Oct 17, 2019
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I tried uninstalling my antivirus (Malwarebytes) and turning off Windows Firewall, but that didn't help. Checked task manager and tried to discern if there were any unknown processes (kinda hard since critical processes have weird names and i cant tell what is what. I've also used a program called "rKill", which has saved me in the past, but not this time.

I'm not sure if this is a problem with the OS because Windows itself shuts down. The PC won't POWER DOWN.

Also, tried booting in safe mode, which afaik, would boot with only the main windows drivers, correct? So not a driver issue?

Also, booted up with ALL hardware disconnected (except cpu and psu). ie, there was no OS involved in that attempt. Still would not shut down.

This issue starts immediately when the rear power switch is flipped, meaning this happens BEFORE anything else happens. I would guess and say there was a short before the front power switch, but the front power switch does work to boot up once the PC is running. If there was a short, then the switch wouldn't function at all, correct? I haven't tried completely removing the power and reset switch pins. If i remove those and it still powers on, would that suggest a short circuit on the MOBO?
 
Oct 17, 2019
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Here are some more tips to try, and no I don't have stake in the company trying to sell you software;)

Thanks for the link. Some of these i have tried, but i have not yet tried to turn off clear pagefile. Also, these are all OS related, some exclusive to Win10; Win7 does not have Fast Startup option. I don't think the issue is OS related, as i have tried powering down with my hard drives disconnected and the problem still occurs.

If you unplug the power button/switch from your mobo, and the same for your reset switch and disconnect everything and the PC still turns on by itself, Call an exorcist. Whatever you do, don't get it wet or feed it after midnight. :)

You aren't kidding!

I am going to try unplugging the switches soon, but maybe not today. What I am noticing now, and for the last day or so, is that my CPU temps are unusually high. Like, right now the cores are all about 30 degrees F higher than normal. And about 20 minutes ago, my CPU cores were acting erratic in Windows Task Manager. At idle. I had nothing running...only HWmonitor and desktop. Again and again, I have tried checking for any malware or suspicious processes and I can't find anything. CPU is definitely acting like there's malware or something, but it is not being detected. Even rKill says there are no suspicious processes to stop.

Could the CPU just be dying? I noticed this AFTER I cleaned all the dust out of my PC. I barely touched the CPU fan. I'm just utterly confused.
 
Oct 17, 2019
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I will try 2 of those today and see what happens. Though I'm losing hope.

I think something is wrong with either my PSU, CPU, or motherboard. I've been noticing my CPU cores are running unusually hot. Yesterday, on first boot up, the cores were hot, but when I rebooted, they went down to normal. When they get hot, there is no CPU usage going on. Today, I tried rebooting a few times, but my CPU is staying hot. Also noticed a few games were running slower than usual. But one of my other more demanding games actually ran quite smooth. I am entirely confused as to what is going on with my PC. I'm just going to start saving for a new PC now.
 
Oct 17, 2019
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Thought I would post an update.

I managed to solve the problem today!

It was a failing power supply!

New PSU seems to be working great! I hope this thread helps anybody that encounters a similar issue.
 
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