A ten-year old window (ref on it = GHL, M04, 3059 & 75ARO16), opened fully and will not close. Web-sites searched for answer and no help. I have added WD40 and tried lifting various bits around the mechanism, to no avail. Any help here please?
John in Shropshire, 15 July 14

John Tucker, July 2014

Check and tighten the torx screw that holds the frame, located where the spring attaches to the bottom of sliding hinge. If it has loosened It can catch and stop the hinge from sliding.

Alan, May 2020