tv led lcd toshiba 32sl738g napis "ci plus key fail"

Hello
I got to repair tv led toshiba 32sl738g and the problem is that in the middle of the screen is still visible "ci plus key fail". In this connector (CI) there was never any card
I tried resetting the settings, re-setting channels and updating the software (up to version 2.04), unfortunately without any effects.
From what I have read on various foreign forums, it is quite common in these TVs.
Unfortunately, no one gives a solution to the problem, except for the proposal to send equipment for service.

This happens when the wrong batch has been used to upgrade the firmware (similar model)
Only replacing the Main plate (SSB) with the only remedy
Link_ CI-PLUS-KEY-FAIL

(' ') (' ')

Quote:

When the NAND-Flash must be replaced, the SSB must be ordered, due to the security keys! (CI +, MAC address, ...).

thank you for the quick reply
But for the sake of accuracy I will add that the TV I received just because of this malfunction.
It is used by an older person, so any interference in the soft (in addition to mine in the workshop) is silent. I will add that the firmware has certainly been correct.
If in the near future there are no other proposals, I close the topic.

Tv returned to the owner unrepaired and now it is unfortunately his worry.
I close the topic.