On my 708 which i think is older had the outer large bearing fail, when it started making a lot of noises it was noticable. Its a common problem I was unaware of or I would have loosened the belt! Blowing out dust will have zero impact.
Its DeWalt. Blowing the crap out won't help. This is a common problem on DeWalt products that have that belt drive. It comes from the factory with the belt way overtightened and the bearing can't take it over time and fails. Very common problem. Maybe, its a cheap bearing as well as this is consumer grade tools not commercial. Also, repeating myself, when blowing out the dust and adjusting the belt, don't make the belt too tight. It should deflect slightly after adjustment.
