Thanks Toneman2121,
however still no result.
I'm able to navigate through the menu when booting with the right arrow button pressed, but I'm not able to select "reset user presets", there is a menu displayed with the entries, "Pedal Call -", "Buttons - ", "Pots - ", Ëncoders - ", "Flash - ", "SDRAM - ", "LEDs - ", "LCD - ", "Variax - ", "Jacks - ".
Navigating to the Flash item and press the save button for >5 seconds but no reaction for the device.
However when the POD has been booted in this menu I'm able to connect to it using Monkey.
With monkey I performed below described actions with the Device Firmware (overwrite user presets followed the steps as described by the wizard):
Flash Memory: Re-install Latest -> no difference, during this action the corrupt bank has been copied from bank 30A to 01A
USB Firmware: Re-install Latest -> no difference
Flash Memory, Rollback to version 1.21 -> no difference
Flash Memory, Upgrade to version 2.01 -> no difference
From the backup and Restore tab in Monkey:
Download and installed Pack Fanatic Bundle File: Studio & Live -> no difference (all banks including 01A are overwritten)
Removed the power plug for 30 seconds, etc.