[Lurchh]

When I connect my Sabre Tiny to the computer, an error message appears saying that the device is not recognised and has malfunctioned. I have tried uninstalling the drivers and reinstalling them but the computer will not recognise it. It had been working for 2 days but now has suddenly stopped. The green power led fails to light so I am beginning to think it is a hardware problem with the device,  however, I can only find one dry joint and it is on the jack socket anyway. I have connected it to various computers, a powered usb hub and my galaxy s3 but the green light fails to light. Is there anything I can do to find out what is wrong/repair it? Hifimediy do not accept returns so it looks like i'll have to fix it myself.
Thanks