There are mainly 2 things that you can check without opening the MacBook’s bottom case
- Battery: To check the battery health there is a free tool called Coconut Battery, which can be downloaded from here https://www.coconut-flavour.com/coconutbattery/
- SSD: To check the SSD Health download SSD Reporter from here https://www.corecode.io/ssdreporter/
3. Keyboard: Visit this website to test if all the keys are working https://keyboard-test.space/
4. Webcam: Webcam can be checked via the internal app PhotoBooth.
5. Microphone: This can be checked from system preferences itself. Goto System Preferences > Sound > Input and say something
Input Level will start to light up, this means Microphone is working fine. If you want to check the clarity, try recorind something in Voice Memos
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6. Speakers: Play any song on youtube and head over to system preferences. Move the balance slider left or right to check the speakers individually
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7. Display: Check the display thorougly for any cracks, chips, dents or dead pixels. To check for dead pixels goto this website https://lcdtech.info/en/tests/dead.pixel.htm