i want to give the downgrade a second chance. After a few years

I read the wiki and get some infos from my TV.
In the service menue i see the firmware 3000.0
and the Backupfirmware 3002.2.
now i guess the downgrade (a few year ago) was successful
yesterday i try to run telnet enabler and DTS sound support (DCA) app from internal memory, but with no success.
Can anybody give me some advice please.
Thank you