Die Oberklasse

Hello everybody,
Please excuse me for writing in English. My German is only basic.
I suppose my case is clearly lost, but just in case ... I ask to the experts. Technical service here is very slow (especially in Christmas)
I started the software (firmware) upgrade from the software update menu the other day. Everything was going OK, but when the actualization/download reached 50% (more or less) it went very quickly to 100% and a message saying that the update could not be done appeared. I could continue using the TV normally until I put it to sleep. The next day, the TV would not start working, with the blinking white led light permanently staying lit.
Is there a way to fix / hard reset / manually reload the firmware update from USB, etc ? ( the screen is black, no access to menus, just the white led blinking all the time )
To be useful to other users, I have to point out that I made the upgrade via wifi, and albeit I succeeded in a previous update (some months ago) this time something, I do not know what, failed. So it seems (I knew it, but I took the risk) a bad idea to upgrade via wifi ... something you all probably know.
Thanks a lot in advance and
Best regards!

As long as you have no working panel (no menu to use) there will be no way for yourself to solve the problem.

Did you try pulling the power cable? It might help not set the Art in standby only, but making it completely powerless. And disconnect every other electronic device before doing the restart.

I have ni other idea so far.

Do you know the latest softwareversion you tried to update from?

Thanks a lot for your answer!
I tried to leave the set unplugged and plug it back later, to no avail. I am not sure of the software version it had. It was from last spring ...
The TV is already in the hands of the official tech service.
As I did not made any strange manipulation, just the standard software update via standard (not service) menu,
the repair is covered by the guarantee. But they told me that it was probably necessary to change the full logic board (€700!). Just for toasting the flash memory it seems a bit exaggerated ... for routers, for example, there are usually ways to access the flash memory and reprogram it externally. OK, modern techno-economics ...
If it happens to be something interesting I will report for keeping the forum participants informed.
Ein frohes Weihnachtsfest und alles Gute zum neuen Jahr!

Hi there again. This is just to report what happened at the end. The service guys were able to reload the firmware without need of changing the logic board. The version they installed is V10.2.4.35, and they told me that it is the most stable version for this set, and I better not try to upgrade again. At least, I will not try to upgrade using WiFi, just USB !

A very curious thing is that they were puzzled by the version of the software that was previously installed in my TV, and the only information they gave me is that, strangely, it started with the letter W instead of V. That version was coming from an upgrade I made via WiFi and the software actualization menu command. If someone can figure out what is this "W" version it would be interesting to hear about it.

Thank you very much again for the help you provide !