I don't know if this will fix your problem permanetly..but I have a 6634-900 Windtunnel, that I am beginning to hate.. Easter night I got so frustrated I took apart the top of the handle, 4 screws, then I put the red switch to the off position. Next, I took apart the actual handle(the very top portion) with a thin flat screw driver...each side at the bottom there is a release..be carefull. Inside I put the componets where they belonged and put it very carefully back together. It works now, but for how long I don't know. The vacuum was almost $300 and has only been used 10-12 times( it is my second floor vac) and I think it is lousy that I can't depend on it and is now out of warranty, and repairs will cost $50 and more likely over $100. YOU CAN DO THIS IT WAS NOT HARD. BUT, MY BIGGEST PROBLEM IS THE ROLLER WILL NOT SPIN.......THE BELT IS SHINY AND THE REPAIR SHOP SAID IT IS PROBABLY DUE TO A FAULTY ROLLER SWITCH OR MOTOR OR SOMETHING....HE WAS NOT GOING TO TELL ME HOW TO FIX THE PROBLEM. DON'T BUY A HOOVER WINDTUNNEL!
MARY LOUISE, March 2008
