Drinkmate 631 *Defective* Carbonator Home Appliance Parts Drinkmate

I believe this is a Drinkmate 631 series (not indicated on the main unit).
Purchased at Costco and used regularly.
Since the bottle is the main part used, the main unit has relatively few scratches and stains and is in good condition. However, there are some stains on the side if you look closely, so please check image 6.

The following are the current conditions with issues:
It is possible to make carbonated water, but the gas level cannot be seen, and although it is supposed to stop automatically when carbonation is injected, it is broken and does not work. Therefore, I used to stop it manually when I heard a click, which indicated that carbonation had been injected. (Tilting it forward stops the gas injection.)
It is not completely junk, but it is a product for those who can repair the broken parts or who don't mind operating it manually, so please consider it with understanding.
Also, please only purchase if you understand that this is a used item.

*The bottle is a consumable item and is not included.
The main unit, power cable, and infuser will be shipped.