He sounds exactly like I was at that age. I failed the 8th grade completely because I simply didn't try. I couldn't bring myself to try. My parents pretty much did all the things you've said you've tried--they punished, they restricted, they threatened, and they pleaded. They also tried the carrot rather than the stick, saying I could have such-and-such which I'd always wanted if I'd only do some damn school work.

Nothing worked. I failed. My school decided, for some reason, to let me go to summer school and then pass me anyway. I really don't know why.

Turned out my problem was depression. My mother finally took me to a psychiatrist and although the guy did nothing but talk to me about his vacations to Israel he took every six weeks or so, he did one thing that helped me more than anything ever has in my life. He prescribed anti-depressants. I never was a very great student anyway, but the anti-depressents lifted the haze and the black cloud enough for me to at least do what I needed to do to get by (there's nothing anti-depressants can do to make you less insanely lazy, unfortunately.)

I can't say that's what's wrong with your son, but I can tell you your story sounds almost exactly like one my own mother would have related when I was around his age. It's something you might want to look into.

A lot of people think depression needs to be caused by something--somebody dies, you get depressed. You're in a bad life situation, you get depressed. And yeah, that kind of depression does happen. But it's not the kind I'm talking about. Clinical Depression is depression for no discernable external reason. It's just a chemical imbalance in the brain, and it can be corrected with medication. Talk therapy helps some people, but for the most part, since clinical depression doesn't have any external causes, talking about your "problems" doesn't help much, since they're not really the cause of the depression.

Anyway, hope this helps.

-- Dave