SamyGO

What is firmware full name and version TV uses right now?
What is full tv model name with letters after 5500?

I don`t remember if D5 series TV has SmartHub. Looked at Samsung site and haven`t found nothing about.
I think this feature is for more expensive TVs (models D6 >) and not for your TV. You cant get Internet@TV with firmware update. That`s samsungs politic. Why people buy new models if they can upgrade old or lower model TV`s. If you really need this feature, you have to buy new TV. That`s all. Business.

Try to change to another model in service menu. But i can`t guaranty that you don`t brick TV.
Also for safety set:
rs232 to "debug"
watchdog to "off"

After that if brick, you can unbrick TV over ExLink easy.