Not Again

I was making the last cut on a finger-jointed board and the board exploded when the blade bit in. It stayed under the guard but jammed the saw to a stop. Luckily I was using board with a clamp to hold it down. I did not see any visible damage, so I tested on a pine 1x2. It did cut, but it felt wrong. The blade no longer stops, it will just keep spinning. It is not not the brushes. Is this the motor itself or maybe a gearbox? Any ideas.