The SO was playing with her solar lanterns one night, using one of my 3 D-cell Maglites to charge them. She forgot to turn the flashlight off, and had it sitting lamp-down on a table so she didn’t see that it was on. Drained the batteries. I bought new batteries and put them in. It doesn’t work. I tried swapping bulbs (there’s a spare in the butt cap), and that didn’t work. I think I tried another bulb, and still no joy. There is no corrosion, and the new batteries are, well… new. I’ve put them in my new LED Maglite.
Remember those plastic five-cell flashlights Radio Shack used to give away every year? (There was a coupon on their Winter flyer.) Those would work for a while, and then stop working for no apparent reason.
Two questions: Is there ‘something’ with flashlights that cause them to simply stop working for no apparent reason? And, more immediately, why won’t my Maglite work?
The cheap crap are built to very loose tolerances and usually stop working because the contacts get out of alignment and don’t touch well enough for current to flow. This shouldn’t be a problem with a real maglite though.
Do you have a multimeter that you can check continuity with? Take a close look at both bulbs to see if the filament is intact. Even a perfectly unused bulb can be damaged by shock so that it no longer lights up. Incandescent bulbs are inefficient. Normally a lot of their waste energy comes out as infrared light. That all got trapped with the head down so potentially there was some heat induced damage that wouldn’t have normally happened (weak solder point letting go, etc.)
The dark side is that it costs $15 for ‘shipping & handling’, plus (probably) ten bucks to send it to them. For that, I can just buy a new one from Amazon.
I do have a cheap multimeter around somewhere, but I’d have to find it. (I should buy a good one, so I’ll know where it is.) I did look at the filaments when I swapped bulbs, but I recall they were intact. But then, my eyes aren’t as good for close-up/small things as they used to be.
I was thinking I should swap heads with another Maglite. If it works, then I know that the battery compartment is OK. If the head doesn’t work on another tube, then I know the problem is there. I can tape some D-cells together and get some wire and pull the bulb to see if it works that way.
But I’m still on the clock, so I’ll have to try that later.
Since my program is chewing on a very large file, I thought I’d check some things.
I’d forgotten that the heads don’t just ‘swap’. Well, they do; but not as a unit with the bulb. But I took the bulb out of the faulty flashlight, and put it into a flashlight that I know works. The bulb is good. I tried the ‘bulb’ (it’s a replacement that’s much brighter – I wish I could find more like it) in the faulty flashlight, and it didn’t work in it.
I shined a light down the tube of the faulty flashlight, and verified once again that there is no corrosion.
The faulty flashlight worked perfectly well until the SO left it on. After that, it stopped working.
I dunno. It the AAA-sized Maglite penlights I have used, the contact between the buttcap (which contacts the “-” pole of the last battery) and the side of the tube can get sketchy, making for unreliable or completely open circuits. In those types, the contact circuit is a spring, a thin sheet spring steel thingie going out to the edge of the cap, and then the tube of the flashlight. Unless the contact leaves are pulled outward enough to really scratch at the inside of the tube, it may not really be making contact.
Dunno if this has any applicability to a larger Maglite, though.
Well, I’ve found the location of the problem. I put the butt cap from another flashlight on, and achieved illumination. Now I just need to figure out why there’s a faulty connection between the battery/spring/cap/body tube.
The larger Maglite has a spring that fits into the open end of the end cap. The circumference where the spring sits is not anodised – i.e., it’s bare metal – so there is contact.
My best guess is the switch may have failed. Really, what’s left? You’ve tested the bulb and batteries.
They don’t last forever, and it’s certainly possible that being left to “bake” in the heat from the bulb was just enough to nudge an old switch into being a dead switch. They are replaceable, but not easily. Seems to be about $5 for a switch and another $10 for the special tool(s). Like the warranty service, it may be more cost-effective to just replace the entire flashlight.
ETA: Good that you found the actual problem. Weird that the butt would be faulty somehow.
I think the problem is between the spring and the cap. Since I’ve tried the spring in two different caps, I’m guessing the problem is the cap. My hypothesis is that in the process of being run down, and then sitting with the switch on with dead batteries all night, there’s a light layer of corrosion that I can’t see in the cap. I’ll get some steel wool later and see if that makes it work.