OS X: CM Storm Devastator keyboard doesn't light up
I have created a fork of the apple LED test script specifically to turn on and off the LED Backlight on cmstorm keyboards. This should also work for anyone who needs to turn on scroll lock on their external keyboards (which is the backlight key for most keyboards).
To use it:

Download the binary and install it in your Applications folder
wget https://github.com/pykler/led-backlight-osx/blob/master/led-backlight-osx?raw=true -O led-backlight-osx
chmod +x led-backlight-osx
mv led-backlight-osx /Applications


Then you can either

run it on the terminal like so
   /Applications/led-backlight-osx # turns the backlight on
   /Applications/led-backlight-osx off # turns the backlight off


OR use an automator script as described in the following answer. Replace the automator script in step 11 with the following.
 ```/Applications/led-backlight-osx```


to create a script to turn it off create another automator script with the following
/Applications/led-backlight-osx off

The details for the automator script are in the edit below.




EDIT: to add this as a keyboard shortcut you must use Automator as in @AlexanderTaylor's answer, in summary:

Launch &quot;Automator&quot; from either Launchpad or Finder/Applications

Choose &quot;Service&quot; type (For Catalina, first choose &quot;Quick Actions&quot; on &quot;New&quot;)

(On the left) &quot;Library&quot; -&gt; &quot;Utilities&quot;, drag &quot;Run Shell Script&quot; to the workflow pane.

At the top of the workflow pan, choose &quot;no input&quot; in &quot;any application&quot;

For &quot;pass input&quot; choose &quot;as arguments&quot;

For &quot;shell&quot; choose &quot;/bin/sh&quot;

Paste in this script:
 /Applications/led-backlight-osx


Click &quot;File&quot; -&gt; &quot;Save&quot;, save it as &quot;CMStormLedOn&quot;

Go to System Preferences -&gt; Keyboard -&gt; Shortcuts -&gt; Services -&gt; CMStormLedOn and click on the shortcut ⌘+ScrLk. (it will show up as ⌘+F14)


Done. Now typing ⌘+ScrLk should turn those LEDs on.