Computer is acting strange

I'm working on a computer that would not turn on period. So the first thing I did was replace the PSU unit. However, as soon as I flip the on switch the fans inside the computer start to spin. I though "ahh perhaps it's already booting up.." I look over to the power button on front of the case and it's not even lit up. Then I thought maybe the LED's were just burnt out so I pushed the button anyway. The button lights up.

There are no beep codes nor is there any video from this machine. I'm begining to think that the issues are far more than just the power supply and perhaps ram as well.

thoughts?

update:

So I said to hell with these useless KVM switches I'm forced to use at work and hooked it up to a dedicated monitor and sure enough, I get video.

however, the issues still presist with the fans constantly running. Even when I shut down the machine within windows.

 

Thanks for the reply David.

to answer some questions:

"So the video issue and booting to Windows is ok now? just checking!"
Yep works when connected directly to monitor. guessing issues with KVM switch orginally.

"I would imagine if you pull the PSU plug cable the fans go off?"
Yep. If I pull the plug everything shut off. Upon plugging it back in the fans fire back up even without booting up the pc.

"you could try clearing CMOS and then re-enter the BIOS default settings (as int time date and make sure the 1st boot device is correct especially if using RAID) then also check the Suspend settings S and S3 and try vice versa."

reset everything back to default and still get the issues with the fan.

as for trying a different logic board, I don't have any on hand so if it turns out that is in deed the issue i'm in bit of a pickle

 

update:

If I take the ram out, the fans appear to be operating as normal.

I get the standard beep code. I'll try a standard swap to see if that fixes the issue.

update 2:

I swapped out the ram and it fixes the issue with the fans auto starting upon plugging in the PSU. however, upon shut down the fans still run. only way to shut them down is to unplug the machine.