everything was working perfect until one day the Display ports stoped.
i had the 2 HDMI's and one of the Display port connected and they were working perfect.
2 hdmi's connected to a Samsung SyncMaster B2230 same monitors. with normal hdmi cables
Display port to a Sony Bravia TV 32". with cable one end Display port and the other hdmi. but i have also a display port converter.
I'm not sure, someone else may be of more help. Maybe driver got downgraded by Windows and reset the settings? You could check your driver version and if it was changed then DDU and reinstall. Otherwise make sure your cables haven't gone bad. Seems like a very odd problem.
I would try to eliminate the DP-HDMI adapter by connecting another Monitor that has a DP port on it and using a regular DP Cable or another HDMI Monitor.
It can either be a bad GPU DP output port or a bad Adapter cable.
If you can temporarily connect a DP Monitor to your GPU card's DP Port and you get video output than you know it is a bad DP-HDMI adapter cable.
Or you can simply try another Adapter cable and see if you get video output.
Also in Windows Settings is your DP-HDMI Monitor/Tv Set showing up? If not then most likely it is your Adapter cable is not working correctly anymore.
Is your DP-HDMI Monitor showing up in Device Manager under "Displays"?