I've been playing around with the GM862 USB v3 eval board. I've been successful in using the GPS part of the GM862 from the USB port of my PowerBook, but I've run into some problems.
However, in order to start the GSM service up, it needs more power than the USB port alone can supply - fine. I needed to find a 5V DC supply that can handle a peak of 2A.
I chose a 5VDC 2.5A regulated plug pack and then had the choice of polarity on the DC plug. The PDF on the web site was for the V2, and there was no indication on the circuit board which one needed to be +ve.
A crackle, flash and pop indicated I had made the wrong choice. I rapidly unpluged the power pack, but it had smoked a SM component - I am guessing it is a diode, but it is beyond identification now. I removed the charred remains and confirmed the board still works with the USB port.
Can someone help me identify this component? In the attached photo, it is the larger one near the ft232rl usb controller.
Also, if anyone has any (general) advice for powering the V3 of this board, I'd love to hear from you. The PDFs online are hopelessly outdated. Ideally I'd like to run this off a 12V DC car circuit, but also incorporate a battery to provide power if the car battery is disconnected.