Problem solved.. Having taken the crank off, and the little trim panel, the 'winding gearbox' fell apart in my hands, the two screws which hold it together had decided to have a holiday from stress, and unscrewed themselves. Gearbox reassembled, with tight screws and home made loctite (the wif'es clear nail varnish.. DON'T tell her! All working now, thanks for the info all. Alec