Hi there,
thank you so much for your comments.
1. Firmware file is definitely placed in the root directory of SD card. In one of my attempt I have even removed the other files that appear after card formatting and left only the firmware file.
2. Firmware file seems to be correct. This is what I have in SD card folder: fwdc209b.bin, BIN file size 10 752 KB
3. YT tutorials - unfortunately my problem is not addressed there
4. Ensuring the battery is full prior update - yes. btw ,through my search I have also found the thread of damaging camera by interrupting the process.
So far, no success.
Through further search I found my problem on other forum:
Why can't I update the firmware on my K5: Pentax SLR Talk Forum: Digital Photography Review
Unfortunately this hokus-pokus method does not work on my camera.
I will try to use the other SD card, but must wait, till shop will open.
To go back of the root of my problem - just wanted to upgrade firmware to be able to use the new SD card of higher capacity 64KB. And found that K-5 (unlikely to K-5 ii) does not read the cards SDXC. If this is true, than I will by another SDHC 32.
Still waiting for tips.