ADDED:
After reading your additions -- wow, I'm so sorry. All this testing to see if something's "wrong" with him and he is just wanting to have it all and do nothing to get it -- no disorders or conditions here.
You note that you can't take away the computer and I get that; they're vital for school now. But can you:
--Limit his computer time to school-use only? This would require one of you basically to sit there in view/earshot of the computer at all times when he is on it. He'll hate that but too bad. You could ease that with a reward system: He gets his homework done to your (and his) satisfaction in a reasonable time frame without going to distracting sites and he earns X minutes of "free play" computer time.
--Limit his time with and access to friends and just plain random "hanging out"? I don't mean forbid friends, or turn friends into forbidden fruit so that he's sneaking out! I do mean having him busy enough that seeing friends must be coordinated and scheduled, so it's not possible for him to "show up late after hanging with friends."
--Create a system where, if he forgets his phone, discipline follows. He needs to feel greater "pain" for leaving his phone at home; it's his own fault he's "starving, tired and angry" because you couldn't contact him. If he leaves the phone today, he loses privilege X or thing Y. Make sure it's something he values enough that he'll feel the loss, like losing a planned outing with friends next time because he forgot his phone and you could not reach him this time. Stick to it and follow through with taking away the desired thing. No yelling or fighting, just matter-of-fact, you forgot, we could not reach you, you lose X, no debate.
--You mention you cannot disable TV (nor should you have to, for the rest of the family's sake) but you can limit HIS viewing. If the thinks that's unfair, well, he has to earn TV like he has to earn computer time. He should come up with a specific list of specific shows he would like to see inlcuding the days and times they are on, and should give you that; don't let him just veg out in front of whatever is on. Then he earns the shows he wants.
--Is it possible he is just bored out of his mind with school? He clearly is very smart and very unmotivated. Schoolwork, in and of itself, is of no interest to him. He may need another school altogether, where he will be seriously challenged in unique ways. I know -- hard to think of another school and greater academic challenge for someone who doesn't want to do the schoolwork he already has. It would be worthwhile, at a time when you are not angry and he is not angry, to sit down and explore calmly his feelings about school; you may find he doesn't care because the work is so very dull to him but he might be up for something unusual. He could be wasting a good brain because of uncreative teaching combined with--well, with his being 14, an age when they can't see past their own noses.
--When you say "we" have been to counseling, do you mean with/for him or as a family? I would look into family counseling with an emphasis on specific strategies for you and his dad to use to goose him along each day.
End of added section....
Sunni, talk to his school counselor. (Be sure to tie the issue to his disinterest in homework -- school counselors usually need some kind of tie to the child's school life to get involved.) Ask the counselor for ideas both for motivating him at home, yourself, and ideas about summer programs, camps, etc. that would get him outside his own little bubble. Kids this age are self-centered, and that's how they're supposed to be to an extent as they navigate who they are, but not to the point they are this isolated.
Another type of summer experience from which he might benefit would be some extensive volunteer work, someplace where he can see how fortunate he really is and how little others really have. He might learn some gratitude that way.
But start with the counselor soon. Summer programs and camps are already filled around here so you may need to get going on this ASAP. And consider seeing a family counselor if it really gets beyond basic teenager apathy. Good luck.
