Great point about the TV powering down the USB ports when it's off. Mine does (light goes out on Keyspan device) so this would seem to rule out the USB approach.

Sounds like I should just cut the DB9 connector off of a URC RS232 cable and splice it together with a two ring 3.5mm plug. Will have to get another URC RS232 cable as the two I have are being used for my Oppo UHD Blu-ray player and Yamaha AV receiver.

I've never seen a three ring 3.5mm connector other than on the URC RS232 cables. Any chance I could find a connector like this or it easiest to just cut the end off a URC cable?

Just curious-what type of crossover DB9 cable? I see several types but don't know anything about these.