Hi,
I didn't find the part on Alibaba. Ultimately, I found the same scanner for parts in the USA that someone could bring me for $40. It had a broken spring that I extracted from my scanner and was running again. It was easier to proceed this way and I didn't have to search for how to calibrate the sensors. Plus, I have some additional spare parts now.
Next time I buy one of these machines, I will make sure that many are sold in my country, it will be easier to look for parts.