Hello,
It sounds like the firmware may have been corrupted, please try to force reinstall the latest firmware. To force a reinstall follow the usual installation instructions and the following.
If you try to load an older version of firmware, or the same
version that is currently installed, the oscilloscope will not load
the firmware and will display a message indicating the firmware on
the USB media is not newer than the current firmware.
You can override this, and force the oscilloscope to load an older
firmware file, by creating an empty text file called "forceinstall.txt"
on the USB media in the root or topmost folder.
Latest MDO34 Firmware:
https://www.tek.com/en/support/software/firmware/3-series-mdo-firmware-v1104
