IPhone – What’s the name of the screwdriver that will open up an iPhone 4

if you still have warranty on it :

I would suggest you restoring the iphone to factory settings and taking it to the nearest Apple store.

else :

I believe there is a hardware issue (loose connection). Since it is a 3G iPhone (warranty may have expired unless you got AppleCare), it is not difficult to open up and see whats going on inside.

Hope it helps!

p.s : When you say 'stroke of luck', things get interesting. You may put your iPhone in Restore mode and then see if iTunes is recognizing it (if you at least have any charge, only then will it be possible to try this!).

The first time you unscrew the screws on your computer, you'll notice there's some blue gunk around the threads. That's Loctite. It's essentially a sort of superglue for screws to help them stay in. The glue adheres the threads to the casing, but isn't strong enough that a decent screwdriver and some wrist action can't break it. I'd probably recommend finding an appropriate bottle of Loctite and then dabbing a bit on the screws and then screwing them back it. That should keep the suckers from comin' back out. :) I'm not sure about prices in Brazil, but in the US a bottle of Loctite (or something similar) should only cost you a few dollars.