Ok How do you Know the Kaon is On ?
The TV switch automaticly to EXT2 and some components get warms

Has a fuse or something blown ?
No

What was the bootloader version before the upgrade ?
Was 2.19v4, then with this firm loads 2.19v3, when getting back to 2.19v4 the deco died

Try Loading The EK version here as this has its own bootloader 2.19v3
Communication dead

Make sure you use Kup230 in engineer mode, and turn off the kaon at the back before running the kup230 then load the bin file then turn the Kaon on.
Tried that. No communications at all.
I've done this a lot of times (one too many )