I would not have made the suggestion to first use WD 40 before disassembling anything if it did not work! Over the last 5 years, I have used this spray to restore operating window mechanisisms without one disassembly. WD 40 is a penetrating lubricaant and if used regularily (every 6 months orso) can keep mechanisims free and operating properly. If a motor or other mechanical fault exists thats the followup. Save yourself a headache, at leat first TRY my suggestion. Sometime a good fart can do wonders! Abe G