I would not perform a firmware update if at all possible, as there are different versions of the device. The first devices (end of 1994) had a YUV output. This was removed in mid-1995. According to the manufacturer's website, there were then devices with YUV output again (but I have not seen any online from this period). The devices from 1997-2000 that I have seen all did not have a YUV output. There are two versions of the TBC, 9.1 and 10 (I can't remember the exact version number right now).
The H-phase button is useful e.g., if the recording window of your capture card is not centered, as is the case with AIW cards, for example. The same applies to the correction of the color shift in the X and Y directions in real time. If you are still editing, this is also possible using Avisynth or Virtual Dub, but it is very useful when recording directly to DVD, for example.
The date of manufacture/year of sale can be found on the white sticker on the back.
A colorbar test picture can be enabled when you press the PIC1+2 and the PIC1/2 button at the same time. To go back to normal function just switch the TBC off and on again.
The T-code button can be used to disable copy protection, time code, VPS, and teletext.
The three memory locations and the default memory location may lose their settings, and a data error will appear on the display. The slots can be saved again with the current settings by pressing the Default or Mem 1 or Mem 2 or Mem 3 button for 2 seconds. The default settings are 100.
The device was part of the basic equipment for dubbing services in German-speaking countries and was also used by broadcasters, from what I have read.
The device is PAL only. No NTSC and no PAL-60.
On the various German-language sales platforms, you can find about 10 devices changing hands throughout the year. The selling price varies between 70 and 400 euros. A fair price would be around 250 to 300 euros. Don't let yourself be driven crazy by the inflated prices that are sometimes asked. I've been tracking the prices for these devices for around 23 years now and think I have a good overview of what they are worth.
The inside of the device looks like this:
https://www.mikrocontroller.net/topic/523231