PC won't turn off...even with holding button

ctbrown

Member
Jan 7, 2006
95
3
71
My PC will intermittently blue screen shortly after logging on (approx one out of three times). After the blue screen, I hit the power button and computer seems to partially turn off, meaning the monitor turns off, but the fans are still spinning and the temp monitor on the case is still lit up and registering a normal idle temp. However, I won't be able to completely turn it off, even after holding down the power button for a real long time. So I must cut the power with the switch on the PSU. I do know that the power button works, since I can turn it on. This is an HTPC and the case does not have reset switch, only a power switch. And also, I do not overclock, everything is run at defaults. And I've also tried replacing the CMOS battery.


So I was wondering if its the mobo, PSU or a driver issue


Specs:
CPU- i3-540 LGA1156 (run at stock speed)
Mobo- Gigabyte P55M-UD2
GPU- HIS H645H1G Radeon HD 6450 1GB 64-bit DDR3 PCI Express 2.1 x16
RAM- CORSAIR XMS3 4GB (2 x 2GB) DDR3 SDRAM 1600
HD- SAMSUNG EcoGreen F4 HD204UI 2TB
PSU- Thermaltake TR2 W0070RUC 430W
OS- Win7 Pro 64
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
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The holding down of the power button to turn off the pc is controlled by hardware on the motherboard. It really doesn't matter what OS is running, there is a chip that controls that in hardware, not software. If you are getting blue screens than start there, but my guess is it is the motherboard. A typical chip used on the motherboard to control the power on/off is the IT8718, not sure what your board uses since it varies, but that chips usually controls things like power on/off, fans, etc.

Looked at the board on newegg, can't see the chip number but the insignia ITE is clearly visible over by the memory slots. That is the chip responsible for power on/off via the button.
 
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Blitz KriegeR

Senior member
Jan 30, 2005
261
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I'd suggest testing the PSU first since that is an easier job than replacing the board. Still, I agree it is most likely one of these two things. If you have another PSU lying around, try hooking up JUST the 24pin atx and the 4/8pin atx to the board and try booting the PC. If it works, the PSU is bad. If it does the same thing, it is most likely the motherboard that needs to be replaced.
 

ctbrown

Member
Jan 7, 2006
95
3
71
I'd suggest testing the PSU first since that is an easier job than replacing the board. Still, I agree it is most likely one of these two things. If you have another PSU lying around, try hooking up JUST the 24pin atx and the 4/8pin atx to the board and try booting the PC. If it works, the PSU is bad. If it does the same thing, it is most likely the motherboard that needs to be replaced.

I'll try the PSU swap 1st. And if that doesn't solve the issue then I'll get a new mobo.

Thanks
 

ctbrown

Member
Jan 7, 2006
95
3
71
Isn't this indeed the BIOS?

If PC won't shut off, the CPU could be failing to run the BIOS.

If this is the case, would re-flashing the Bios help (It's current) or is there any other fix aside from getting a new board? Sux cause the board is out of warranty. Unfortunately I let it sit around for more than a year before building a system with it. And I can't find the specific board on newegg anymore, so I'll probably have to replace it with something that has a different chipset and having to reinstall windows.
 

stevech

Senior member
Jul 18, 2010
203
0
0
If the CPU cannot execute code, you can't reflash the BIOS, unless some boards have a clever trick with an AUX CPU.

Of course, the temperature sensor can shut down the CPU, e.g., if the die isn't thermally mating with the heat sink.

All the other stuff applies too - assuming no BIOS action on POST. Bad power supply, connectors/cables, broken trace/socket/pin, etc.
 

ctbrown

Member
Jan 7, 2006
95
3
71
If the CPU cannot execute code, you can't reflash the BIOS, unless some boards have a clever trick with an AUX CPU.

Of course, the temperature sensor can shut down the CPU, e.g., if the die isn't thermally mating with the heat sink.

All the other stuff applies too - assuming no BIOS action on POST. Bad power supply, connectors/cables, broken trace/socket/pin, etc.

After forcing a shutdown/restart with the button on the PSU, I can still get into the bios set-up, make changes and they stick...so wouldn't this mean that the CPU is still able to execute bios code? And the PC doesn't do this every boot...just very often.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
Isn't this indeed the BIOS?

If PC won't shut off, the CPU could be failing to run the BIOS.

Nope.
The one chip responsible is that ITE chip. It controls all the power on/off , startup of voltage regulation, sends the power good signal to the supply, etc.
The only interaction it has with the bios is the bios can tell that chip to turn power off, but it can't stop it from turning off power via the hardware switch.

If the ITE chip is locking up then that would mean the chip is faulty or the power it is being supplied to run the chip, the 5VSB is faulty.
The same chip also houses the hardware for the hardware monitors, floppy controller, serial ,parallel ports, KB, mouse, ps/2 ports so check those connections to make sure they are not shorting out something causing the chip to malfunction.

Here is a sample schematic of all the things it controls




iteb.jpg
 
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ctbrown

Member
Jan 7, 2006
95
3
71
Ok so swapping the PSU partially solved the problem...meaning the computer will now properly shutdown after crashing (no hard lockups requiring the switch on the PSU). However, I still get the BSOD intermittently shortly after the OS loads.

So now I need to figure out if it is the a hardware issue with the Mobo or not. RAM tests fine after running memtest overnight continuously. I've reinstalled the lasted drivers from Gigabyte. And no malware detected using 3 different programs. So this just leaves the HD and the GPU...how do I check those?
 

nenforcer

Golden Member
Aug 26, 2008
1,767
1
76
Have you tried booting a minimal system by removing everything except for CPU, 1 Hard Drive, onboard video and 1 stick of RAM?

Also, since it appears that board doesn't support the onboard video of your CPU try moving the video card to the second PCI-E x16 slot (x4 electrically) as I read reviews on that motherboard which said that improved stability from BSOD.
 

ctbrown

Member
Jan 7, 2006
95
3
71
Have you tried booting a minimal system by removing everything except for CPU, 1 Hard Drive, onboard video and 1 stick of RAM?

Also, since it appears that board doesn't support the onboard video of your CPU try moving the video card to the second PCI-E x16 slot (x4 electrically) as I read reviews on that motherboard which said that improved stability from BSOD.

I'll start with switching graphics card slots...and if that doesn't bear any fruit , then I'll try single sticks of RAM, switching between slots and sticks. Should I also test some known good RAM from another system?
 
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ctbrown

Member
Jan 7, 2006
95
3
71
So I think it's working now...I've rebooted into Win7 dozens of times to trying to make it crash and ran prime for awhile as well...but it seems stable.

As mentioned previously, I traded the PSUs between the unstable HTPC and my son's PC. Swapping a Thermaltake TR2 form an Earthwatts380. This seem to solved the hard lockups in the HTPC, but the BSOD would still occur in the HTPC on every 3rd or so reboot when loading windows. And the funny thing is that my sons PC (now with the PSU from the unstable machine) seems to be totally OK. So problem was partially solved.

Next I tried took the CORSAIR XMS3s from the HTPC and traded them with the Crucial Ballistix from my office PC..and guess what...both HTPC and office PC are stable.

So I guess this Gigabyte board is very picky about what components its paired with...or time will tell if it becomes unstable at a later date.
 

Meghan54

Lifer
Oct 18, 2009
11,684
5,225
136
I'm not surprised taking out the TR2 helped.....that series of power supplies is a very old group regulated design almost a decade old and is built with some very cheap components. You did yourself a favor getting it out of your system.
 

pejantantanggung

Junior Member
Apr 30, 2018
1
0
66
Hi, i also have this issue

but it only happen when it fail on CPU stress test , im overclocking

now its all back to normal when i found stable voltage

i just wondering what can cause this, usually computer should turn off by pressing power button for 5s

thanks

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