Open Broadcast Software worked for me until I recently re-installed win7(damn you winsxs bloat). After reloading OBS all the screen capture was a black screen. Window and monitor capture worked but that is not the same as capture from a full screen game. After searching on the internets and from OBS FAQ there was no proper solution.
Then I tried to re-install the video drivers. The GPU is an Radeon HD3650 and is aboard my satellite P300 laptop. The first choice was the lighter installation package. The results for OBS was still a black screen. Then for kicks I tried the full installation. The Catalyst control panel added another 100 MB and usually never gets used. The magical full installation must have code components that allow OBS to hook into. The black screen is now replaced with my smiling kerbals
TL;DR
OBS Black screen remover = Install the full GPU driver suite with Catalyst control panel.