SamyGO

If you want to test if Hyperterminal is working, just connect send to receive (short out the contacts on the jack plug) - you should then get characters echoed back (twice if you have the "echo" option checked).

Hey, you needed to see TV's debug messages first I think. Unless, I am suspecting that you cannot create RS232 connection properly.
I don't know windows programs. But you have better to check connection settings I think like speed / stop bits...

Thanks for the screenshots but it does not help us in this situation.
Weird, it's needed to be some output at terminal; at least all of other models including A series and even CI+ types has eloquent output at ExLink cable.
I wish to have a access to your TV model but I haven't. There is nothing to do unless if we (you) can't find to way to drop shell. Sorry.

You needed to try every possible way. But it looks like creating Telnet Connection with this model of TV is problematic.

So you connected the TV at last. But it looks there 's no chance to drop linux shell on your model.
Is your TV support Content Manager applications? If yes, you can write program that dumps flash image to USB flash.
If your TV is not supports applications, than there is nothing to do. There is no way to reach flash practically. You can dump flash by soldering wires directly to your flash chip which is mounted to TV's circuit. It requires good soldering skills and exactly void your warranty with big probability of brick your TV.