My 16 year old son is sabotaging his school by not turning in/doing homework assignments in all of his classes. He does well on quizzes and tests but tells us lies and excuses why the homework isn't done. His dad and I are divorced but work as a team no matter which house he is staying at. He knew going to college was expected (and saved up for) but if he continues to get poor grades he won't be accepted to any schools. We make him pay for his phone on our plan with the money he makes working on weekends. He is very involved in Marching Band at school and has made valuable friends through that. I don't want to take that away as it keeps him occupied and around positive influences. What can we do at this point as I don't want to micromanage his time but he has not shown any self-discipline to get his school work done.