sounds like my son! constantly into things that i dont want him into. we had an old tv, and it was fine when he touched it, yet we still told him to stop, and he was finally being nice to the tv, which of course means now, we have a new tv with one of those sensitive screens.. and im scared hes going to ruin it. still, he hasnt hit it with anything... but we are trying hard to keep him away.
if you are the creative type, you could make your own tv stand... my husband ended up doign that because our new tv wouldnt fit into our old stand, so my husband just made one. it took him 2 evenings after work, and its beautiful LOL.
the thought is, now, to create some sort of a door or something to protect the tv when we arent watching it.
the computer is another thing our son wanted to play with all the time. i just tried to make a habit out of putting something in front of it so he couldnt push the buttons. distraction, punishment, etc wasnt enough, so i had to practice deterrance!
if there is ANYTHING at all you can put in front of your tv and computer to prevent little fingers, do it. it doesnt matter if its a chair, a box, a pile of books, whatever.
sooner or later, he moves onto something else, trust me. :D currently my son would MUCH rather play in my plants (OOOO DIRT!) than touch the tv or computer. if you can, get him something with buttons that he can play with while youre using the computer. a toy piano thing, an old keyboard... something so he can pretend hes working like you are! :D
consistent. just keep trying. it shouldnt be more than a month and he will be distracted getting into something else.
do you have a Christmas tree? perfect time to get his mind off the tv LOL.
good luck mom. let me konw what works!