Standard replacement parts like refrigerator water filter, defrost thermostat, control thermostat, control board and water valve assembly are easy to obtain and are offered in General Electric internet site and other online suppliers like Amazon. Refrigerator water filter is an essential refrigerator part that must be changed regularly, this is the part that has an expiration or duration, usually 6 months.
Internal compressor parts at normal operation dont break very easily and will last for countless years of use without breaking. Usually when the compressor fails, the whole unit will be completely replaced since the whole compressor is closed and you cant easily open it without chopping the body casing using a hack saw. But in some instances like in third world nations they attempt to open and fix it, changing only the ruined components like piston, piston ring, shafting, etc to save money.
There are also refrigerator parts that can easily fail. Fragile parts such as the evaporator door, meat tray cover which is constructed of fragile plastics that can easily crack if you are not cautious. If you have a classic model or vintage GE refrigerator and you need to have some components to fix it, it will be hard to obtain most of its components, especially new replacement parts. What you can do is to look for secondhand or used GE appliance parts.