So, long story but the basic problem is no display except for a brief flash of a number of random dots on switch off. Nothing otherwise. This started a while back with various lamps out on playfield, so having had similar issues on this machine caused by the ribbon cables I said to reseat them, at which point the whole machine went more or less dead. A new set of ribbon cables later and everything is good except for the display. Mate checked voltages from dmd driver which he reckoned were well off where they should be. Replaced the driver with a new one and still the same, as in no display. Today we swapped the DMD with my known working one just to eliminate it and as expected, no difference. All LEDs on all boards are doing what they should so we are now a bit at a loss of where to check next. Any suggestions greatly appreciated! Cheers, Graham