CI+ card can't authenticate after running service menu

[kbatay]

I have a TV model UE40ES6100, and a CI+ card. A few days ago I entered the service menu, and after that my CI+ card can no longer complete authentication to my provider -- the TV just displays "Authentication in progress".

I have done that in the past without problems, so I suppose whatever happened is related to the firmware version. The TV was running firmware 1040 when the problem started, since then I upgraded to 1042 and the problem persists. The TV is also rooted, I can telnet to it etc.

If I downgrade the firmware, would that stand reasonable chances of solving the problem with the CI+ card? Anything else I should try?

Thanks in advance for any help!