Panasonic TH-42PW4 Plasma Display just can't communicate with my cable minibox
So I have this ancient Panasonic TH-42PW4 Plasma Display that came with my furnished apartment. I really don't have the money to replace it, so I'm stuck with it. It works very well, it's just pretty darned obsolete.
My cable service (Cox) moved to miniboxes last year, and the two devices just don't have the means to connect. The minibox has either coaxial or HDMI output. My choices of input (see attached screenshot) on the Panasonic are: 1) Component/RGB + Audio R/L, 2) PC + Audio, 3) Serial, or 4) AV Terminals In (this has S video + Audio R/L + another little video port)
Are there any cables or converter boxes out there that will somehow transmit video AND audio signals from my minibox to my display?
What I've tried so far: I found some cables on Amazon that I thought would do the trick, using the Component/RGB input, but the colors didn't match, and though I tried plugging them in every possible combination I had no success. I also found a cable that connected HDMI to the PC input, but that was video only, no audio.
Thanks for any help!