Computer will not boot unless unplugged when off

[bat27man]

I'm having an issue where my computer will not boot if I turn it off and do not unplug it. I tried replacing the CMOS battery and then when that didn't work I just about 5 days ago replace the motherboard with a brand new one. I came home from being out of town for two days and I had left it plugged in but it was off and it will not boot. It's not shutting down while it runs. It's when I shut it down if I don't unplug it the next time I go to start it it turns on and all the fans run but the computer doesn't boot and there's no flashing on the hard drive activity light. I have been fixing this by unplugging it anywhere from 10 minutes to 2 hours so it will boot again. Any suggestions?

 

[sarcophagus_macabre]

Power supply? What is your power supply? Turning it off doesn't help?

 

[cherry blossoms]

Has it always done this or is this a recent development?

Posting your hardware specs and what OS you are on would probably allow others to have a better chance to help you narrow down the problem.

 

[bat27man]

Power supply? What is your power supply? Turning it off doesn't help?

I have a thousand watt ocz fully modular power supply. Basically if I shut my computer down and leave it plugged in the next time I go to start it all of the fans will come on but it will not boot. To get it too boot I have to literally unplug it for like an hour or more. Also when trying to start it up today it is turning itself on and off three times and then staying on but not booting. That's got to be power supply right?

 

[bat27man]

This started a couple months ago.

4790k I7
ASUS Sabertooth Z97 mark 1... I did replace that thinking it was a CMOS issue with an asrock z97 pro4
OCZ 1000W PSI
GTX 980TI
64-bit Windows 8.1 Pro

 

[Mark RM]

either PSU or video card, a basic any watt psu will let you test that theory if you can borrow one.