N8 Power Keys Works ONLY When USB Cable Connected???
 

Device cannot be powered unless there is USB cable connected. When i connect USB i can power the device and disconnect USB - everything works on the device (except power button). When the unit is ON, power button does nothing, but when USB connected it can be used normally.

I have checked power key ways, everything OK there.

What could cause this strange problem?

check battery bro......................................... may be bsi is problem

battery is OK, tested with another unit.

Phoenix says: ST_KELVIN_CAPACITOR_TEST: "FAILED"

Where to look next?