[Solved] Mainboard hangs after connecting Harddrives

Hi to all of You,

I am new to the Mackintosh community and do not really understand the problem I'm having. Subsequently I'll try to tell you the steps I did and maybe one of You knows the problem.

My Hardware:
Mainboard: Asus z87m-plus
CPU: Intel core i5-4670k
GPU: Nvidia gtx 760
Ram: 16gb ddr samsung ram
HDD: Western Digital Green 2tb
SSDs: Samsung 840 evo 240tb (old one with Windows 8.1 installed)
Crucial mx100 256gb (new one where I installed OS X)

Installation:
Before the installation I removed the WD and Samsung Hard drives.
Then I booted from an Unibeast stick and installed OS X. On reboot I had to enter the flag "-no-zp" into Unibeast to avoid Kernel Panic. I was able to install all necessary drivers but I could not get Chimera to work. After I gave up on Chimera, I installed Clover which worked great.
So after I got OS X to work, I wanted to plug my Windows drives back in, but after I did that, my Mainboard became incredibly slow. It took about 1 or 2 minutes to do anything like loading UEFI BIOS or an OS. I tried CMOS reset, Resetting BIOS settings etc, but nothing could improve the situation. I am able to boot into Windows and OS X (but now only with the Unibeast stick; for some reason clover does not work anymore). After I shut down Windows, everything stays powered on for a minute or so.
So the last thing I tried is updating the BIOS, but it did not improve anything.
Might it be hanging in POST or something like that? Did I destroy the main board while plugging my hard drives back in? Might it have anything to do with Clover?

I really hope someone can help.

Kind regards,
Dorian

Mainboard hangs after connecting Harddrives

I was able to resolve the problem. It seemed that the power connection to the DVD Drive was not connected properly. After disconnecting it and plugging it back in, everything worked great.