A.Beforeyouuseorchargetheflashlight,pleaseunscrewthetailcaptotaketheinsulatingfilmoutfromtheflashlightandtryagain.B.Thetailcapneedstobescreweddowntightly.Pleasetryswabbingthecontactsinthetailcapwithsomerubbingalcoholtothoroughlycleanthem.C.Iftheflashlightstillcannotbeturnedonorcharged,connecttheflashlighttoapoweredchargingcable.Ifthelightturnsonwhilebeingcharged,thismeansthebatteryisdefective.Ifthesestepsdonotwork,pleasecontactusandwecantrytoassistyoufurther.