Of course, refurbished MacBooks are fully tested. In fact, when a MacBook is getting refurbished, testing is one of the most important stages.
A refurbished MacBook is submitted to:
- hardware tests;
- software tests;
- thorough checking of all components.
Typically, most parts pass these tests without an issue. If any faulty part is discovered, the refurbisher will either fix it or replace it. For instance, a loose wire on a MacBook motherboard can easily be reconnected but a broken keyboard needs to be replaced.
Once the repairs are done, a refurbished MacBook goes through the entire product testing process again. Note that refurbished MacBooks go through the same testing process as any new MacBook does. It is put up for sale only after passing all functional testing.