I watch on TV可以把on换成by吗?on与by表“通过‘时有何区别?

on是“我从电视上看到的”的意思,改成by后就什么都不是了.
by是通过某种媒介、方法、方式的意思
如：by bus,by car.I wrote to him by email.I find the word by looking through the whole book.
on是通过⋯⋯上的介绍,从⋯⋯上看到的意思
如：I see the information on the newspaper.
如有问题,欢迎继续追问：）