Yes, usually "bit rot" occurs in older RAM modules found on 128K chips; you will likely need to desolder all chips and put new ones in sockets. I wouldn't recommend just doing one and leaving the rest as chances are more will fail quickly.
Socketing the RAM as Byrd says is highly recommended. Should any fail in the future, even if you don't replace all of them now, it will be much simpler to fix since you won't need to do any soldering later on.
So I found a mac 128k that im thinking on getting but it has an error code 040001. Anyone know how to fix that? Just trying to know how to fix before getting it.