your High voltage regulator circuit might be bad and is in an overvoltage condition. stop trying. you might permanently damage the displays. do this to check: unplug the displays and measure the test points on the regulator/driver board. make sure your DVM is set to measure 300v range. TP4 should be 230vdc or so. TP2 is the output to the displays and should be no more than 190vdc. BE CAREFUL PROBING THIS CIRCUIT! THE VOLTAGE IN THIS AREA IS HIGH AND IT HURTS! Rick