LOL Franco, I can dig deep into a pallet load of (pick a product) and I will pick the faulty one every time. My curse.

In all likelyhood, that thing has 1) peltier device 2) voltage regulator 3)a couple of diodes to prevent back feeding the peltier and 4) battery and fan. It would be my guess that you've lost the voltage regulator chip and nothing is making it to the USB. Not much can go wrong with a peltier block. I'm assuming the stove was wired correctly from the start. This is easy to test with a meter but in your case, Biolite should replace it. I still liked your reviews and am hoping to see this thing work as it should.

I don't know what kinds of stores you have there but a $10 multi-meter....which I'll happily walk you through its use....will tell you exactly what is coming out of that USB port. You'll use it later to test batteries and lightbulbs, etc....many uses.
Wal-Mart, Radio Shack, auto parts stores all have cheap meters.