When you say hidden defects lisod na ma recognize doh kay mao gani gi tawag nag hidden. And besides you cannot say laptop is in good shape if di nimo suwayan. Naa man gud nang batch defects, or problem mo occur di dayon or intermittent bah.
So for me when buying laptop my suggestion is consider pud ang brand and the warranty. Better get brand new as well kaysa 2nd hand.