NO RIME OR REASON FOR THE MONITOR TO GO BLANK. ONLY WAY TO GET IT BACK IS TO HARD POWER DOWN  THE CPU. POWER BACK ON AND THE MONITOR WORKS OK FOR A WHILE, SOMETIMES A HOUR SOMETIMES ONLY HAVE TO CLICK ON A ICON AND BLANK IT GOES. WE HAVE TRIED MONITOR TESTING, ETC..  NO GO. ANY ADVICE. THNAKS. WE ARE OUT OF BUSINESS WHEN THIS WORKSTATION GOES .