My internet disconnects every time I turn my tv on. Can anyone help?

Do you have a UPS? I used to work in an office that had them, and every time I printed something (laser printer) the computer would shut down. Turns out the software could be set with varying levels of sensitivy, and mine was set to the very sensitive setting.

Is your TV between your computer and the WiFi access point? I've seen that happen before, although it was a microwave that caused the interference.

Call your cable provider, the tv and internet are on the same frequency. They will be able to walk you through the steps to change your wifi's frequency.

Not quite sure what a UPS is.
My laptop and tv are the same distance away from the wifi router.
I've already changed the wifi's frequency but the internet still disconnects.
I have also tried replacing the tv with other televisions and the internet works fine, but as soon as I put the original tv back it disconnects.

A UPS is a battery back-up system for computers so that you can shut them down before they crash in the event of a power failure. It does sound like a frequency conflict if only the one television occasions this problem.

All electronics generate radio noise. Usually, it is low-power an not strong enough to interfere with other devices. The FCC has guidelines on how much RF (radio frequency) noise electronics are allowed to generate.

It sounds like your TV exceeds those guidelines by a good amount.

Can this suddenly happen even if it's worked for over a year? If so, can it be fixed? Thanks.

I think I have figured out the problem. When I turned my tv on earlier the power blew and after that my tv wouldn't turn on again. So checked the power adaptor and there was a strong smell of burning.
I'm hoping if I get a new adaptor then the tv will work again.