I've had a MIDVERB IV since 1/96.There was a year or so where I had the same problem; it would go out for 5 minutes,then on,then off for a few DAYS...A tech looked at it and told me it wouldn't be cost effective to fix it 'cause the display is one piece with the circuitry(just telling you what he told me).Anyway,as time went on the problem became less frequent,and I can happily report that I have had total illumination since the dawn of the 21st century(on the MIDIVERB that is).Hang in there...