How do I convert any TV to a smart TV?
I would think it would depend on what your idea of a "dumb" TV is. If you have an older tube TV, I'd think you'd be out of luck. Short of finding a device specifically made to connect to a coaxial cable. I have a flat screen TV I bought right before "smart TV box has came out. It's a nice picture but doesn't have a lot of functionality built into it. What it does have are USB and HDMI ports.
Instead of buying a new TV with a lot of functionality, I initially purchased an inexpensive Hybrid DVB Android Set-top Box mini PC Dongle for around $50, and connected it to one of the USB ports. I then purchased a keyboard that connected to the MK808 via bluetooth, and permitted it to be to control remotely from the comfort of my couch. The Hybrid DVB Android Set-top Box allowed my TV to connect to the internet and it expanded my TV's functionality by letting me watch Netflix, youtube, and surf the internet. Unfortunately I found I wasn't able to download and store an adequate number of movies for my uses.
After being frustrated with the limited use of the Hybrid DVB Android Set-top Box I purchased a laptop for $250 and connected it through the HDMI port. I took the remote keyboard I purchased for the MK808 and connected it to the laptop. When I switch over to the laptop as the video source, the TV basically becomes a monitor. I can watch Netflixs, surf the internet, download movies, etc.
Since then I've been content and satisfied with my TV's functionality and operation.