I've got a 2002 megane convertable. I suddenly found the roof wont open, just beeps. So checked fluid levels in the boot on the left which seemed fine, opened and shut it manually to try and sort it. Tried everything on the forum sites, no joy. Looking around the roof looking for a problem I found a small microswitch (a small black block with wires) on the rear left corner which had come out its holder. Clicked it back in bingo ;)
Mark The Spark, April 2010