Biostar TB85 Help

Hi,

I just made a rig with this Biostar TB85 and i have some problems, maybe someone can help!

1) When i power on the rig is taking two short restarts and only after that is booting, any idea why ?

2) If i have powered risers like this one https://www.shopem.nl/images/producten/PCI-USB3-01/usb3.JPG , do i still need to power the mobo with two molex ?

3) Are there any particular BIOS settings for Biostar TB85?

4) Is ok to power 1 riser with 1 SATA cable ? https://images-na.ssl-images-amazon.com/images/I/51mseFbW05L._SY300_.jpg

Also with the first run, i am able to mine few minutes then is crashing..

I have used Jukebox's v4.rom to flash the cards, sapphire nitro+ rx 480 8gb oc (used it before on another rig with different mobo and cpu and is working like a charm)

Thank you!