I had a similar problem with my middle child (now 5). He is obsessed with the TV and utterly unresponsive to anything else when it is on. We limited it to half an hour a day, and I gave up watching TV in the evening before he went to bed, and it seems to have worked. I can now watch TV in the evening and he carries on playing, and kids programmes are limited to only after homework and before dinner. However if you have tried this and it didn't work then I would be unplugging it, or putting a parent lock on so it can only be switched on with the remote (my DVD player has this function) and hide the remote. Good luck