: Play a speaker test at maximum volume to check for rattling or blown drivers. 2. Deep Dive: Battery & SSD Health
Unlike a new machine, a used Mac's most critical "consumables" have already been partially used: tips for buying a used macbook
: Open a full-screen white background to check for dead pixels, lines, or spots. For newer models, verify if True Tone is available in Settings; if it's missing, the screen has likely been replaced with an inferior third-party part. : Play a speaker test at maximum volume