I too had the problem where the shredder would only work in reverse.  I unplugged the shredder.  Using a flashlight, looking down in from the top, in the center of the slot where you insert the paper there is a little white tab/sensor.  One single shred of paper was lodged behind that sensor.  Using an straightened out paper clip bent so there was a hook on one end I was able to fish out that single shred of paper from behind the sensor.  I plugged it back up.  The machine now works perfectly.  Hope this helps.  Jeffrey
                 Jeffrey Jaggers/ ANTIQUENTUCKY on eBay
                
 September 2012