Mr. Blue said:
I have an L1P and v2.5P....they have both been through 2 sets of batteries. Over the weekend the 2.5 started pulsing as if going out of regulation, so I popped in a new battery. It is now WAY dimmer than the 1.0 version (even with another new battery in the 2.5)....all contacts are clean/tight...any ideas?
Mine had that problem from the start. Initially it was believed to be the tailcap but even with the tightening of the retaining ring, it didn't seem to work.
It could be the connection in the head which seems tight but maybe its not inside. Try applying pressure with 2 fingers on the head at different points , if its the same problem as mine, sometimes it will become brighter, sometimes it will become dimmer.
I'm not sure if you can fix it even if you find the problem, maybe you can get it exchanged.