Is my powerboost 1000c faulty

so with nothing else plugged in except a micro usb soldered to the usb/ground the low battery light stays on?
i have tried different micro usb connector, i have tried different mains adapters all have the red low battery light as soon as its plugged in.
i have even removed the micro usb and plugged it in directly to the powerboost and still have a red light?
am i doing something obvioulsy stupid or is it broke?
any help would be great.