Nothing to fancy or drawn out here, just plain and simple advice to avoid losing out.
I recently used a well known courier company to deliver a printer to a customer, the printer was in full working order when i listed it and packed it. (boxed and inside a box for peace of mind) yet when the buyer recieved the printer she actually phoned me to say that the printer wasn't working.
I issued the buyer a full refund inc p&p and she was happy to hold on to the printer until i contacted the courier company to find out what they wanted me to do with the printer as i wished to claim compensation for the printer, only to be told that as the recipient had signed for the delivery and as no complaint was made at the time of delivery there was nothing i could do.
So the moral of this story is (as silly as it seems) if you recieve a parcel,  before you sign the delivery reciept OPEN IT, and if need be PLUG IT IN, but most of all CHECK THE CONTENTS and make sure your happy.
This may seem extreme (especially when the delivery guy is at your door, sighing and tapping) but thats the company's policy and i would imagine other couriers have more or less the same policy.
DONT LOSE OUT

P.S  Sadly the same has to be said (due to some unscrupulous ebay sellers out to make a quick buck) about recorded delivery items, i recently signed for a recorded delivery item purchased from an ebay seller, everything on the outside looked fine.....? envelope sealed, no sign of tampering but when i opened the package, well i had just signed for a package containing tissue paper....REALLY. 
I would be interested to hear if i am the only "victim" of this kind of scam, i say victim as paypal decided in favour of the buyer as he had 'Proof of Postage' recorded delivery.
It turned out to be the most expensive tissue paper i have ever bought.
Thanks for taking the time to read this and if it helps just 1 person from losing out then its been worth while.