how to tell if a brushless motor is burned?

[honchoscaler]

i just purchased a second hand novak goat brushless combo and the yellow wire unsoledered itself off the motor, dont know what happened, but i tried soldering it back on and for some reason it doesnt work anymore...the esc powers on great but when i press on the throtle the blue light on the novak bec dims out and nothing happens, i tried several different batteriesand still the same result.. now does this mean i burned the motor?? or is it just a bad connection????