HELP: after downgrade tv don?t show any text

[juusso]

You can`t do it w/o risk.
I wouldn`t suggest you to use FFB once more, because you probably get same situation.
Try manual way. here is no safe way left. FFB was the safest...

[erdem_ua]

I think you needed to have ExLink cable.
Than you can watch what is wrong with new firmware.
You also needed to update your u-boot code to avoid bricking in any way.
Than you could try FFB tool or flashing by hand without risk

[juusso]

apolo7, can you give some logs from USB you used for upgrade with FFB (if not deleted)?
U-boot, kernel and fnw were restored because you copied required images to USB. I just need logs to confirm that.
I do not remember if switching to "februar" firmware deletes partitions, i made some tests few months ago and as i remember, u-boot and TOP debug menu were working, just enter to shell was limited by firmware - just ctrl+c did drop to console. Only installation deletes 2,4 and changes 5 partition, switching not.
So you need to solder/buy cable and to check if you able get either to u-boot or debug menu.

[juusso]

So we can see from log that images for accessing Top debug menu and u-boot are flashed successfully. Now to be 100% insured, you need Ex-Link cable.

[juusso]

Yes, errors are quite normal.
Now, try u-boot and TOP debug menu. Just confirm if you able to get in.