QI wireless charging

I have a Nexus 5 and a Nexus 7 v2 and discovered they support wireless changing via QI standard. Bought one of these http://www.dx.com/p/qi-x5-mobile-wireless-charger-black-298118 and it worked great. Ordered a second one, but noticed the packing was different: first one was in a cardbox, second one was just in a plastic bag. They look the same thou. But when I plugged in the second one it did not work, no led was lit and it did not work. Was about to RMA it, but then I dissected it instead.

 The board is similar to this http://www.dx.com/p/qi-wireless-charger-pcba-circuit-board-green-351931 but is missing some components.

I could not see a problem and was about to give up when I noticed the usb socket was slightly loose. I re-soldered all the pins and was able to make it work:-) And I saw why it had happend: the usb socket is 2mm too "high" so when the lid is fitted it presses on the usb socket.

I used a carpet cutter and cut away some plastic from inside the lid to make room.

The first one I got does not have the usb socket this "high", so it seems they have slight different internals or the pcb's are assembled differently.