I've had this smoker for 2yrs now. It's made some of the best smoked meat I've ever had. The last 2 smokes I've noticed my wood chunks are not burning and turning to ash. They are blackened. The smoker in turn obviously isn't producing the smoke it once has in the past. I know by looking at the chunks that they're not get enough oxygen to burn/smoke into ash. Here where it gets odd. I haven't changed a single thing since I used it the first time. This includes the damper position in the upper smoke chamber or place/position of the smoker itself. It hasn't moved a mm since I put it in my barn. Why now am I not getting the chunks to burn down? I'm almost ready to drill a couple holes in the side in the lower chamber