Qbeam switch malfunction

[hafcanadian]

Some time ago I got a Qbeam 3 C-cell flashlight to keep in our Explorer. It was very rarely used, but the other day I noticed it was on just sitting in its spot in the rear pocket of the driver's seat. It looked like low beam, but the batteries were down just a little. On unscrewing the base I found corrosion just inside the tube and around the base's edge threads, and an apparent thin copper boot over the base's spring wasn't green but was in pieces. I cleaned out the corrosion and will treat the corroded areas with DeOxit, but in testing continuity on the base, I find that no matter the switch button position there is continuity between the spring and the base's aluminum threads. With fresh batteries the light will not switch off, and apppears to be stuck on low beam.

Any idea how to disassemble the base to see if it's repairable? There is a plastic plug in the base, surrounding the spring, with two holes in it such as some devices you can unscrew with snap ring pliers, but I can't get that to budge. Do I dare use PB Blaster penetrating fluid around the edges of the plug… assuming it does screw into the base?

 

[hafcanadian]

No ideas? Hard to believe this sort of tailpiece switch composition isn't familiar to someone on a flashlights forum. 😕

 

[hafcanadian]

Ok, I managed to "rip out" the stubborn threaded plastic plug that was corroded in, and found its purpose was just to keep the contact spring centered. Further down the base was a metal retainer also with snap ring holes, and it wouldn't turn either. PB penetrating fluid overnight didn't work. I then invented a scheme where I moved the point of a screw around the retainer's edge at various places, while applying an etching tool to the screw head. The vibration worked, sinking the fluid and breaking corrosion's grip. It took awhile to unscrew that switch retainer from deep in the base. But now there is some sort of apparently plastic insert in the bottom, with no snap ring holes, and the switch has to be immediately underneath it. Hopefully pressing on the rubber switch button will dislodge the insert and finally expose the switch innards for any possible fix. Any experience and advise would still be appreciated, although no one here has yet offered it.

 

[hafcanadian]

Switch case is out, finally. Looks like there is one intact chrome contact tab emanating from one side and that contacts the surrounding aluminum base innard (positive circuit). But an apparent contact on the opposite side of the switch case is eroded away entirely. I'm guessing it went down the case side in a slot and underneath to contact the spring (negative circuit) that would press against the last of the 3 C batteries. I may try to disassemble the plastic switch case, and engineer a new negative contact from a chromed 1/4" wide piece of metal. Dissimilar metals may be why the original dissolved, and the interior of the base is so corroded. So much for anodizing.