All OS If you were buying a pre-owned mobile (from someone you don't know) ...

[PoBoy]

... what would you check/look out for ?

Any tips / suggestions. Esp if you learned it the hard way, LOL.

 

[Sumi]

First and foremost, always clear entire data from boot menu.

 

[princeoo7]

physical condition. EMEI Number. bill of ownership. and if possible, run the antutu test 3 to 4 times and check the battery drain.

 

[saggyN73]

Try and buy a phone with at least few months of warranty remaining and proper bill. So if you face any problems after few days, at least you get replacement from company.

 

[Siddharth1]

try to look out for screen replacement... it could prove costly mistake specially if it's not done by authorised service centre.