How to calibrate?

[daisizhou]

Hi Guys

Please forgive me for posting for help again,I have been trying to enter calibration mode for the past few days, but I have failed so far.
VT650 is still in a faulty state, the pressure value changes irregularly and cannot maintain zero position.
It looks like I need to enter calibration mode and recalibrate to be successful,I read the FLUKE user manual, but it does not describe how to enter calibration mode. It only mentions sending the unit back to FLUKE for calibration.
This console has lost its warranty. It belongs to me personally and I do not plan to send it back to Fluke for repair because the repair cost is too expensive.
I hope that through my own efforts and the help of my friends, I can return to normal.
In order to describe the fault more accurately, I took a video and pictures




In the manufacturer's firmware upgrade description, I vaguely saw a little clue, but I don't know if it is useful. Maybe it can only be analyzed by reverse engineering the firmware. But I am a beginner. If you can reverse the firmware, I hope you can help me. Thank you.