Fluorescent Flashlight Repair

Pretty soon, I’m going to have to change the name of this place to “Secret Underground Flashlight Repair Center”, but whatever.

Symptom – approximately 20 year old combination fluorescent and incandescent flashlight suddenly loses the fluorescent side. Incandescent is fine. Try the obvious stuff – new batteries, fiddle with the switch a few times, remove and replace the fluorescent bulb a few times. No joy.

Disassemble, completely.


Visual inspection: broken wire on the transformer. This shot is actually after desoldering two of the surviving connections…


I hauled out the desoldering braid to completely and cleanly remove the transformer, then I soldered some bare copper wires (probably 28ga – salvaged out of an old PBX installation) to the leads. Reassembly is the reverse of takedown, but much, much more fiddly.  Once its finally back together, switch it on and it works.


I really need to go back in there one more time and squirt a bunch of silicone to stabilize the wires and hold the transformer in place. It’s a miracle the transformer didn’t break loose before now. Roughly twenty years of rough handling finally caught up with it.

3 thoughts on “Fluorescent Flashlight Repair

  1. Bev Kennedy

    I have one that looks VERY similar — mine just all of a sudden won’t turn on at all (none of the functions work). HOW did you do the complete disassembly?

    1. eriklscott Post author

      I’ll do another teardown and take better pictures this time, but the basics are:

      1) Remove the swing-out stand. It’s one screw. Remove slowly because a pair of spring loaded balls will pop out. Remove balls and springs.

      2) Remove screw in the side of the flashlight.

      3) Remove the two screws in the back/bottom of the incandescent head. This is the critical step – the head basically holds the whole thing together. Then remove the screw that forms the tilt-up head.

      4) Lift away the tilt-up shell, and only the shell. Leave the bulb holder behind.

      5) Elevate remaining part of tilt-up head to about 45-60 degrees. Pull halves enough to remove the tilt-up.

      6) Now pull the halves apart like any piece of electronics. Pick the thumbswitch up off the floor. 🙂

      7) Cautions – circuit board is connected to the tilt-up contact via a very short wire, so be careful when separating the sides.. The PC board and the reflector ride in specific grooves molded into the housing. When reinstalling the thumbswitch, the narrow tab points to the tilt-up end. And remember to put the fitting for the lanyard back in before you button it back up. A tiny bit of modeling clay will hold it if you don’t have three or more hands.

      The circuit splits neatly into two paths at the switch – if both halves are dead (and died at the same time!) then you’re probably looking at the battery contacts (including the one in the slide-out battery compartment cover). Otherwise, the incandescent side is dead simple and ought to survive anything.

      1. Bev Kennedy

        Thanks much — Had a little “detour” but am going to attempt mine this weekend should have the time by then).
        A visual of your disassembly would be phenomenal.
        Thanks again!

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