My initial investigation indicated the belts and idler pulley were ok. I then watched your video and proceeded to disassemble the dryer. I found that the right rear roller assembly had seized up. To not have the others fail, I ordered 4 replacement rollers from your company ( around 4pm on Friday) and they were on our doorstep around noon on Saturday !!! While the unit was open, I then cleaned out the dust, etc that had accumulated over the years, especially the blower wheel which had become quite packed with dust. I then began the reassembly with occasional reference to your video. The biggest issue is access to the rear of the roller plate and getting at the idler pulley to reattach the belt as it is tight and awkward. DONE and running !