I bought new case and bought new monitor. And monitor says that "No Cable Connected". I tought that there is some issue with HDMI cable, so I bought VGA-DVI adapter and tried to connect it with VGA(DSUB) cable to DVI input (monitor has got just VGA and HDMI), but it didn't help. I tried monitor with laptop and it was working with bought cables. I would think that GPU is broken, but what bothers me that lights on keyboard and mouse also doesn't work. So could be issue with motherboard or CPU or PSU?
Btw I don't know if it can have something to do with that, but first I accidently connected 8-pin CPU cable other way around (end for PSU was in MB and etc...) since bought plugs are same. But nothing has change when I fixed that and I think (hope) it couldn't do any harm(?).