UPDATE .....MAY 7, 2012
To my grandson Braydon....
I started having issues with a short again, and this time found the battery holder positive terminals were "collapsed" at their mounting point in the plastic holder, preventing the battery itself from making contact. There were three very small screws to remove from the end of the battery holder, allowing removal of the holder's end cap, and therefore access to these terminals. A miniature slot screwdriver was used to gently pull these out a TINY amount. This allowed the batteries to make proper contact and corrected the 'shorting' problem. Light is working great again ! One
I bought a package of 2 'tactical style' small flashlights from Home Depot for roughly $10 US.
They are great, powerful little lights, but within 2 weeks started shorting out during use. Very annoying. Thinking it was a bad on-off switch or a loose connection to the batteries, I started snooping inside the thing. What I found was a worn spot on the heatsink, at the point where the battery holder 'nose' or 'nub' connector makes contact. If you'll look in the photos you'll see the tiny worn place on the heatsink, which to me looks like it was spray painted on with a metallic-like paint. That's over simplifying how it's constructed, I'm sure, but you'd agree, I think, if you saw it with a magnifying glass, as I did. Solution was to drop a small amount of solder into the center of the heatsink, creating a solid area for the battery holder nose pin to make contact. Worked like a charm.
Step 1, disassemble. Unscrew the front end-cap, revealing the silver colored head you'll be working on
Step 2, unscrew the head from the after-part of the flashlight.
Step 3, turn the head on it's side with the led light down, exposing the back side of the heat sink where the trouble spot is.
I've supplied 3 different shots of this, and if you'll look at dead center of the heatsink you can see a tiny worn spot.
Look closely and you'll also see a tiny hole towards the edge of the contact area. I'll assume this is a source for ventilation
to help the heatsink work best. During soldering, you'll want to avoid covering this hole with solder.
Step 4, First, drop a small bit of solder onto the center, (2 pics of this step)
Step 5, using your soldering iron, spread the drop of solder around just a bit. (another 2 pics of this step)
You're done ! Except for re-assembly, or course. I'll trust you can do that without pictures.
One last tip. When putting it back together, I like to use a lttle lube on the threads, in this case, good ol' vaseline!