Headscratcher. Machine wont immediately power back on after being shut down.

When I shut down the machine cold, it wont power back on for a minute or so. If I wait about a minute, it'll boot and it operates normally. When I try to power it back on right after shutting it down, all I get are the lights on my keyboard, nothing on the motherboard at all. No fans, nothing.

So, motherboard or power supply? I've never had any random shut downs or anything like that. I'm assuming if it was a motherboard issue, I'd probably at least get the power supply fan when I try and power it on.

Couple more bits of info: 1) If I try to power it on. In order to get it to boot, I need to hold the power button. When I release it the lights on the keyboard turn off. Then I wait a 60 seconds, and it boots. 2) It restarts just fine, even when the BIOS cuts power (ie. when I reset the overclock).

My money is on a bad power supply.

It's looking that way. I hooked up my three year old PCP&C 750 and it didn't have any trouble firing back up. Granted I didn't have power to any of my drives, but still. Hooked up the Seasonic and it immediately refused to power back up after I powered it off once it reached the same point.

The thing is, who knows how long it's been this way. I almost never turn it back on right away unless I accidentally shut it down.

Ok, so I set it up with the other power supply. It does almost the opposite with this one. For a cold boot, I have to hold the power button for a couple second before it'll power on. When I shut it off and go to turn it right back on, I don't have to, it powers right up. Granted it's a few years old, but it's 750 watt (and PC Power & Cooling), so it should be more than enough for the sig rig.

Got a replacement coming tomorrow hopefully. Here's a recap:

Seasonic:

- Powers on when the system is cold.
- Will power on immediately if I try to start it up after a shutdown if the system hasn't been on very long.
- Once the machine has warmed up, it won't power back on immediately after a shutdown, but after a minute or so, it will.

PCP&C:

- Will not power on when he system is cold. I have to either press the power button several times or hold it.
- Always powers back on if I try and power it back up immediately after shutdown. Regardless of how long the machine has been on.