Connect power LED on, but still not working (no 12VDC Trigger)
3.5mm TS phone (phono) connection.
Ensure the 3.5mm connection is fully inserted (seated) into the connect 12v trigger port and also ensure the projector (or other trigger source) is connected and fully inserted (seated) as well.
Ensure the voltage present on the 12 VDC trigger are within the range of 5-12 DC with a multimeter. The center pin (or tip of the TS) is positive and the outer contact (or sleeve of the TS) is negative. If the voltage polarity is reversed then change the wiring to be correct, if the voltage is too low or too high out of the range then change your trigger source or provide a dc-dc conversion into the 5-12VDC range for proper operation.