Yes, that's usually the issue. Often those "salvaged" parts seem to work well enough (with a good power supply, at room temperature) and then after a while all your shipped units start failing...
That's if they're not just straight up a different (or non functional) part that's been re-marked and then you find yourself re-working hundreds or thousands of boards!
That's if they're not just straight up a different (or non functional) part that's been re-marked and then you find yourself re-working hundreds or thousands of boards!