This is a good video. I recently cut some dados on my PM 2000 with a somewhat dull set of cutters. The belt started to squeak on startup, I knew it was loose. But I had the blade in the raised position and couldn't figure out how to tension the belt. This video shows you can't do it that way, have to lower the blade to tension it. The booklet should say that, or even just put a little sticker near the lower mount bolt telling you to lower to the blade to tighten the belt.
On mine the blade got so slow it stopped so I tighten belt and then the motor smoked and burnt up so I removed motor and pulled the motor out of my 1hp craftsman saw and did a few mods to get it to fit and now it will cut 3 in Oak like butter.
Same thing happened to mine after about 200 rips of mahogany, Just tightened the belt and continued on. I'm wondering if someone who can't figure this one out quickly should even own a table saw.