Originally Posted By: pmackSee if this helps not sure what kind of switch is in it.
Forward Clicky (tactical style): With forward clicky, you can depress the switch partially and the light will turn on. If you half press it quickly, the flashlight will change modes. The momentary on feature allows you to use the light for short bursts or click it for continuous on. If you want the flashlight to remain on, just press the switch until it clicks. If you want to change modes, you cycle through the modes before pressing the switch a full click. The disadvantage of a forward clicky is, 'if the light is clicked on, you must turn it off to change modes.
Reverse Clicky: Reverse clicky switches must be clicked on before you can change modes. The flashlight does not turn on until the switch clicks. To change the mode with a reverse clicky -turn the light on with a full click -then to change modes, a half press while the switch is clicked on and you will advance to the next mode. With reverse clicky switches, you do not have the momentary on feature...it's just clicked on or clicked off,
If you look around a little you can find this is a common problem
http://atnowners.com/thread/536/ir-850-pro
http://www.atnowners.com/thread/437/atn-ir850-pro
Both of those threads just died, leads me to believe operator error.
Are you sure it is even on?
I tried it all and even took the first one back. I solved the problem by aiming it real high in the air and shoot in the Lower Halo. If you need to see real far you can by tilting down just a little.