I’ve got an SB115 I found at a thrift shop. Got home later and popped a 9V into it and discovered to my delight that it had a screensaver! Very cool, I like to sit it next to my TI-89 for contrast.
I found a Japanese-market tv [1] but don't think it runs off 9 volts very well.
[1]: https://www.amazon.co.jp/-/en/HT-SB115-65UB10PB-Speaker-Blue...