I brought a Blackberry from a chap on ebay. Item No 130461995039 (if you want to look).
I know I should have checked the phone out fully but it looked OK from from the outside. However it has clearly been taken apart lots of times and only has 2 screws holding the insides together. There should be 6! as you guess it does not work!
I have emailed him and he has said no chance of refund. I have opened a dispute with ebay and paypal but I don't hold out much hope. It was £150! Its not the money its the fact that my son is heartbroken.