Computer turning on by turning on the power supply switch

[gragas]

cpu: AMD FX 6300
mobo: ASRock Fatal1ty 990FX Killer AM3+
Video: XFX Double D R9-270X-CDFC Radeon R9 270X 2GB 256-Bit GDDR5 PCI Express 3.0 x16 HDCP Ready Video Card
psu: corsair cx750m
os:windows 8.1

Yesterday I turned off my computer to clean my computer including the power supply switch. After cleaning, I plugged the cord back into my power strip and turned on the power supply switch and this caused my whole system to boot! I reset the cmos and made sure system stayed off when the power is back is checked off in the bios. I am not sure if this is power. However that did not work. so I took out the power and reset jumpers from mobo to make sure front io was not causing the problem and computer still turned on by flipping the power supply switch. however power supply does not turn on when nothing is connected. I am not sure if this is power supply problem or the mobo.

update: Sorry for the confusion.
@clutchc: The problem is that computer turns on by flipping the power supply switch while the power switch for the case is disconnected from mobo.
@ko888: I meant to say [power off] is already selected as default

 

[clutchc]

I kind of lost your logic there at the end. But if the PC does not turn itself on when the power button wires are removed, the problem would have to be the case; its push button. Leave the wires disconnected and use a screwdriver tip to momentarily sort the 2 pins that the power switch went to. If the PC starts normally, the case wiring/button is at fault.

 

[ko888]

... I reset the cmos and made sure system stayed off when the power is back is checked off in the bios. ...

That's an ambiguous term. Do you mean its check box is unchecked or do you mean it's checked?

Restore on AC/Power Loss
Select the power state after a power failure. If [Power Off] is selected/checked, the power will remain of when the power recovers. If [Power On] is selected, the system will start to boot up when the power recovers.

 

[gragas]

I kind of lost your logic there at the end. But if the PC does not turn itself on when the power button wires are removed, the problem would have to be the case; its push button. Leave the wires disconnected and use a screwdriver tip to momentarily sort the 2 pins that the power switch went to. If the PC starts normally, the case wiring/button is at fault.

Sorry for the confusion.
The problem is that computer turns on by flipping the power supply switch while the power switch for the case is disconnected from mobo

 

[gragas]

... I reset the cmos and made sure system stayed off when the power is back is checked off in the bios. ...

That's an ambiguous term. Do you mean its check box is unchecked or do you mean it's checked?

Restore on AC/Power Loss
Select the power state after a power failure. If [Power Off] is selected/checked, the power will remain of when the power recovers. If [Power On] is selected, the system will start to boot up when the power recovers.

sorry for the confusion. I meant to say [power off] is already selected as default

 

[ko888]

... I reset the cmos and made sure system stayed off when the power is back is checked off in the bios. ...

That's an ambiguous term. Do you mean its check box is unchecked or do you mean it's checked?

Restore on AC/Power Loss
Select the power state after a power failure. If [Power Off] is selected/checked, the power will remain of when the power recovers. If [Power On] is selected, the system will start to boot up when the power recovers.

sorry for the confusion. I meant to say [power off] is already selected as default

If that setting doesn't work properly then there is a problem with the motherboard or its BIOS (i.e. that Power Off BIOS setting is being ignored).

 

[gragas]

should i try updating the bios?

 

[ko888]

should i try updating the bios?

If you're not already running BIOS Version 1.30 then yes.

 

[clutchc]

Sorry for the confusion.
The problem is that computer turns on by flipping the power supply switch while the power switch for the case is disconnected from mobo

If the PC starts with the case's power button disconnected, I'd say that the PSU's permissive circuit is permanently on. That would lead me to say that the PSU is at fault.

Test it by disconnecting the PSU completely from the PC. Then power up the PSU. If the PSU's fan spins simply by flipping its switch on, it's the PSU that is at fault.

 

[ko888]

Sorry for the confusion.
The problem is that computer turns on by flipping the power supply switch while the power switch for the case is disconnected from mobo

If the PC starts with the case's power button disconnected, I'd say that the PSU's permissive circuit is permanently on. That would lead me to say that the PSU is at fault.

Test it by disconnecting the PSU completely from the PC. Then power up the PSU. If the PSU's fan spins simply by flipping its switch on, it's the PSU that is at fault.

... however power supply does not turn on when nothing is connected. ...

The OP has already tried that.

 

[gragas]

i fixed it by disabling "turn on fast startup" in the power option. LOL

 

[Mick19]

i fixed it by disabling "turn on fast startup" in the power option. LOL

I know the post is old but thanks for solving this problem. Turning off fast startup in Windows 10 settings fixed this for me too!