(This applies to the ICS that has the green power light and manual potentiometer.)
There are two possible reasons a light will not come on when power is applied to the ICS:
1) The black (gate -) and white (gate +) wires are crossed. Make sure these two wires are not touching.
2) Some power supplies have a strong voltage spike or transient signal at start-up from a cold start. Once all the internal capacitors of the power supply are fully charged, the light can be toggled off-on without problems.
Two possible tests:
- Toggle the power relatively quickly (over a few seconds) on-off-on after the power supply has run for a few minutes and see if the lights come on.
- Toggle the power off-on after the power supply has been turned off for several minutes (possibly even hours in some cases).
This problem was corrected for lights built after 1/1/2010.