PC switches on for a split second then off while shutdown


Established Member
I recently inherited four old Core2 Duo desktop machines from work who were replacing them and giving them away. I've distributed three of them around members of my family to replace ancient old machines, while I was going to use the other as a home media server.

They all seem to work fine when powered on, but they also all seem to behave oddly while shut down. Every now and then, apparently at random, they will power on for a second or two - the fans will spin, lights will flash - then shut down again. If I press the power button they all power on with no problems at all.

I suspect this might be some kind of 'wake on LAN' type behaviour, but I've never had any experience of configuring this so I don't really know how to go about fixing it. There's also the worry that it's a sign that the motherboards are about to die.

Does anyone have any ideas what this is and should I worry about it?

Greg Hook

Moderator & Reviewer
Is that not a setting you can disable in the BIOS?


Established Member
There might be... but the IT department have left the BIOS password-protected. I'll ask them if they remember what it is tomorrow...


Established Member
Resurrecting an old thread...

So I got the BIOS password from IT and disabled all wake on LAN options, and all the PCs are still doing the same odd thing of powering on for a split second when shut down.

My useful IT department said that it must be that to the power supply coming in to them is intermittent as they should only do this when the power is first switched on to them, but if this was true they'd cut out when powered on as well, wouldn't they? They don't!

I really think this must be a software / BIOS setting rather than a hardware fault as it's happening on all of the machines I've been able to get hold of.

They are all RM machines running Win 7 Pro 32-bit. BIOS is Intel DQ45CB, version AAE30148-303.

Any ideas gratefully received! Thanks!


Outstanding Member
A BIOS reset would get rid of the password and any special settings in there.

The latest video from AVForums

Amazon Fire TV Cube Gen 3 Review: Coming Soon
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom