You have pushed it on but the light is dim or remains off
Open up the microlight. If the bulb is black then it is burned out and needs to be replaced with a new one.
If the microlight won't turn on and it has not been used recently, your battery may have run out. Simply replace the batteries and test the device. If the device turns on then the problem was a bad or dead battery.
If the microlight has sustained any trauma and features are not accessible, the microchip within the casing may be damaged and should be changed.
The light bulb may not be matching the polarity with the logic board. Simply removing the light bulb and switching the ends in the input will fix this problem.
You are able to turn on the light but it fails to remain on
If the light is on the first setting, the chip is programmed to shut down automatically to sustain battery life. If this occurs on the second or third mode, then there may be an issue with the battery.
The batteries may have a loose connection with the contact spring. A possible solution is to bend the contact spring slightly so that the spring connects with the battery while in the case. If the contact is not the problem the light bulb may be burnt. Replace the light bulb.
You can turn on the light but it shuts off immediately after releasing the trigger
If the light only stays on as pressure is applied, then the microlight is still in factory signal mode. Holding down the button for 15 seconds will remove the factory setting and enable the user to access the high, low, strobe, and signal settings.