monitor goes black and no cable connected apears on screen

Hey ive been having the following problem only while playing games the monitor wil go black from time to time and flash no cable connected I have a BenQ Gl2030 Led monitor witch runs a resolution of 1600 x 900 my Graphics card is a gigabyte Geforce GTX 650 ti boost ive tried updating the drivers and testing the GPU with OCCT but nothing comes up it only happens when i play games i can hear the game running in the background but cant see a thing

Ok im going to run a game again and see if it throws out a bsod

Hey I've ran the game with the same results screen flashing black and no cable connected appearing on the monitor but no bsod though so I went and set the game graphics to its lowest and it did not happen again have been changing one setting at a time now to try and figure out what's been causing the problem but have still had no luck downloaded 3DMark and ran that aswell but still the problem does not reapear it only happens in games

What can i use to monitor my temps

Ok thanks will come back to you thanks for all the help so far