Testo Datalogger 175H1 - Firmware upgrade went wrong - Dead

[Sorama]

hi guys (and girls),

So I succeeded in f*cking up a rather expensive datalogger (temperature and moisture) while upgrading it to new firmware.

I did the firmware upgrade using a Windows VM within my MacOS and during the upgrade the virtual machine (VM) disconnected/lost connection (I think) and the display of the logger went blank and seems dead.  Not a single reaction of the (single) button to light up the display.

When restarting the software utility for firmware upgrade, this tool does not see the logger anymore (neither in pure Windows environment).

As I am not into flashing/software/processors in general ( I used to repair audio for a few decades in the past century) I'm a bit lost in how to solve this.

What could have happened? Bootloader gone?
firmware wiped but no new version?
What would be the purpose of that 10 pin header/connector?

I did some basic measurement on the pcb and noticed than the xtal of the processor (a TI MSP430F5529, datasheet: https://www.ti.com/product/MSP430F5529) is not running, nor another small xtal.

Included some pictures of the pcb ...
logger is running on 3 * 1,5 V batteries (in series)

Anyone out there to help me understand what happened, what are the chances to revive and how would that go?
FYI, I have two other identical (running) loggers.

Tnx