Question Pc turns on without pressing the power button

status1

Distinguished
Jan 1, 2009
1
0
18,510
Looks like there are no more desktop forums here so I have to post in the laptop section

I have a Lenovo desktop pc that I bought a few years ago as a backup in case my regular pc dies or has a problem so I have it connected with a KVM switch
I had no problem with it until yesterday when I turned on the power strip the Lenovo pc turned on by itself I thought maybe some stuff I had on the side turned it on by accident so I let it boot up and shut it down normally and it was off for the rest of the day Today it happened again and there was nothing around the power switch
So I decided to look into it I unplugged the connector coming from the power switch but it still turned on as soon as I plugged in the power cord
Than I read some comments about the BIOS setting maybe causing it but I did not make any changes to it so I did not see how that would cause it

After some thinking I thought about the CMOS battery if maybe that is low that would allow the BIOS settings to behave differently So I took it out and it measured about 1.48V which is about half of what it should be
I had a new battery available so I installed it and now the pc no longer turns on by itself
Could that have been the cause ?
 

mrmike16

Honorable
Looks like there are no more desktop forums here so I have to post in the laptop section

I have a Lenovo desktop pc that I bought a few years ago as a backup in case my regular pc dies or has a problem so I have it connected with a KVM switch
I had no problem with it until yesterday when I turned on the power strip the Lenovo pc turned on by itself I thought maybe some stuff I had on the side turned it on by accident so I let it boot up and shut it down normally and it was off for the rest of the day Today it happened again and there was nothing around the power switch
So I decided to look into it I unplugged the connector coming from the power switch but it still turned on as soon as I plugged in the power cord
Than I read some comments about the BIOS setting maybe causing it but I did not make any changes to it so I did not see how that would cause it

After some thinking I thought about the CMOS battery if maybe that is low that would allow the BIOS settings to behave differently So I took it out and it measured about 1.48V which is about half of what it should be
I had a new battery available so I installed it and now the pc no longer turns on by itself
Could that have been the cause ?
It seems that the new battery fixed it, so yes that indicates that it was the cause. I'm not sure why you're posting this, but on the other hand it may help other users who have a similar issue. I would also recommend for that purpose to post your computer model, not just the manufacturer, and the version of Windows it is running. It could be that just by removing the coin battery (And by doing so resetting the motherboard) you fixed the issue, so it is possible that even with the old battery it would be fine now. But being with half of its remaining power, it is a good time to replace it.