Martin did a thorough examination of the ventilation system from beginning to end. The reported lack of ventilation when running regular speed and turbo speed has been solved. No, it was not due to dirty filters or because a turkey got stuck in the intake. The problem was three of the five supply grills were closed.
I know it can feel a bit drafty at the shooting line, but that is the price you pay for clean air. Remember the yellow turbo button is not necessary as long as the smoke is not too thick. If you don’t care about breathing lead particles go ahead and shut the vent, but make sure to open it when you leave. Martin tried to direct the air flow just over the head of a 6 foot person. If you are taller and are annoyed by the draft consider redirecting the fins as opposed to closing the vent.
Thanks for reporting the problem. Glad it was a simple fix.