TV can only stay on built in Wi-Fi for 15 minutes before crashing.?

I have two different Vizio EA70i TVs and both have the same issue. When you load the Netflix built into the TV it will load the app about half the time, and when it does load it will only play any given video for about 15~30 minutes before crashing out. I've tried contacting Vizio, and their response was essentially, "Your TV's aren't in warranty anymore, and resetting them didn't work, so you are out of luck." Does anyone have any other ideas?