Before to start you can help me with info about your TV. Troyan telnet enabler does not damage tv by it self, but if you enter wrong commands to console, then you might damage TV.
I know plasma PSxxB850 with firmware T-CHU7DEUC has been successfully downgraded with help of FFB. I`m going today to release v0.3 version of this app, with improved code to avoid bricks. If you help me, i add support for your TV too.
1. full firmware version you use (ok, i know, it is T-CHL7DEUC, right? If it is T-CHLCIPDEUC - no support because of CI+)
2. Some output from your TV (connect over telnet and enter commands). Use EN locale on pc, better copy-paste from here to telnet directly.
3. It would be great that you make some dumps to USB and attach here.
Are you ready?
4. Enable telnet with SamygoTelnetEnabler as Trojan
5. Give me what you get in console from commands given in 3.
6. I write what you need to do next.