If you don't change O-rings, be sure you have plenty of lube on the original O-ring. Use a thinner lube like Nyogel 760. Otherwise, you will think you have tightened the head, and have not fully done so. This may result in failed mode changes or unexpected results when quickly tightening and loosening.
If you have a TAD light you have one with the wider spaced deeper threads which I find still need cleaning, but are easier to clean than the original NDI. First scrub the threads using a cotton swab dipped in 91 percent alcohol to clean the threads inside the head and on the barrel of the mating battery tube. Be sure to clean the end of the battery tube and its mating contact area on the head's circuit board, too. ( Be generous with lube after cleaning BUT NEVER get the lube on the head end or mating surface on the circuit board.) After the Q-tip cleaning and before reapplying lube, take round WOOD toothpicks dipped in alcohol and run it around the grooves between the threads several times. Keep using fresh toothpicks until you see no black material on the points of the toothpick. This cleaning/polishing of the threads made a tremendous difference in the operation of my light. After cleaning, reapply lube. You need less lube on the threads than you do on the O-ring.
Remember that if the head is loose, NO MATTER HOW BRIGHT THE LIGHT IS, you are in user defined mode. It may look the same as the HIGH mode only because it was unintentionally set near the HIGH end of the ramping sequence. To ramp downward in user defined mode, you must quickly tighten and loosen the head - TWO TIMES (the first time ramps upward). The only exception to this would be if the light is already at its birghtest user defined setting. Then, only one twist and loosening will be needed to get you ramping downward.
Any unexplained behavior of the NDI can be explained by one of two errors:
1. Incomplete tightening before loosening.
2. NOT waiting 1/2 second for the light to switch modes, before doing a twisting tightening/loosening operation. If you have failed to wait 1/2 second after intending to switch modes, and then apply a tighten/loosen of the head, you will get results consistent with the mode you were previously in. For example, if the head is loose and you tighten the head hoping to get into high mode, but don't wait the half second needed to switch, should you then loosen and tighten quickly, the light will begin to ramp. This happens because you didn't give the light time to get out of the user defined mode into hgh. It will not go into strobe mode as it would have, had you given it the time needed to actually change into high mode before you loosened and tightened a second time.
REMEMBER the delay required for mode switching is not a mistake that was built in the light. Without taking time for the delay, the light has no way of knowing what you really want to do with your tightening or loosening actions. If you wait 1/2 second after either tightening or loosening, the light changes between user defined and high modes. If you don't wait a half second between tightening and loosening , the light changes an action within that mode: in user defined mode it ramps; in high, it switches to strobe. It is that simple.
The MOST important thing to remember about ALL NDI lights ...........
Excelent Tinkertoo ....... now enjoy it
