Introduction: Modest Improvement to a Harbor Freight Led Flashlight

I picked up a sweet little 9 led light from HF for $5 and it was kinda flaky, shake it and the light went out, so I'd thought I'd post my improvement.

Step 1: What's the Problem

The positive connection is a spring loaded pin pushing against a blob of solder. High resistance and just poor contact.

Step 2: I Had Thought to Just Use a Mini Connector

But had none on hand. So I grabbed a 4-40 nut and tinned it up.

Step 3: Disassemble the Flashlight.

Unscrewing the ring with the hex opening let's you remove the led module. Now just solder the hex nut to the central solder pad.

Step 4: Okay

The nut makes a tight socket for the pin on the battery compartment, it also compresses the pin farther, so now no matter how hard I shake or drop it the light doesn't flake out anymore.

Comments

author
chrissnyder12345 made it! (author)2017-07-22

Just fixed my new style HF flashlight. Was dim and wouldn't get bright even if I knocked it. Looked inside with batteries out and saw white corrosion between the LED ckt bd and case. Trick was getting the ckt bd out because the front doesn't unscrew. Thought there might be a screw on ring holding the front on, so grabbed the front ridge with pliers, tried to unscrew it, and promptly snapped off a chunk.. then I could get a knife under the lens and pop it off... then the board popped out along with a reflector. There are four small beads of solder that contact the ckt bd to case when it's assembled. Wire brushed the edges of ckt bd and inside of barrel, put it back together and it works. I suspect the hokey connection between the barrel and ckt bd gets bad - will check others for corrosion.. maybe can spin the ckt bd/LEDs a bit without popping out the lens if not corroded. As far as I know this didn't have batteries leaking but some I had did and I never kept track which ones (have about six of these). The notch in flashlight doesn't matter, but sand the edges a bit as it's SHARP and will stick leg if put in pocket.

HF flashlight.jpg
author

When breaking off the piece, break it toward outside of barrel so the circuit board/reflector don't get stuck.

This ckt bd makes contact with the barrel with 4 small beads of solder at the edge of the board. This one had corrosion - took it apart then wire brushed contacts on board and inside of barrel and it worked fine. A better fix might be soldering some very fine wire to at least one of the solder spots that contact the barrel. I think aluminum starts oxidizing when current passes through a connection (is why have to use non-oxidizing compound when hooking up cables in a circuit breaker panel).

author
BrefelanDesigns (author)2012-05-10

I used the LED module in one of my projects. Unfortunately the one LED flashlight I had the LED side didn't unscrew... so I have to at it with pliers... which was surprisingly easy...I think these are made out of cheap (thin) aluminum.

author

Not sure if you get notified of this but see above to get the LED bd off when the front won't unscrew.

author
AlbertW32 (author)2017-03-17

Nice article! You really are the expert. It is hard to find the budget and good laser flashlight now.I found the Gearbest <a href= http://www.gearbest.com/laser-flashlight-_gear/>best laser flashlight</a> is good quality. What is your idea?

author
Gunther45 (author)2015-12-13

No respective but why not just get a Cree or PX module and through it in there? I use HB for Free Shears and tape Measures. The torches would be just for housings. Just saying.

author
chrisbaker (author)2010-10-20

In case anyone is wondering, these are made slightly different now: the bodies no longer unscrew at the light end (only the button end) and there is now a spring soldered directly to the contacts on the circuit board where the LED's are attached. The battery holder only has metal contact tabs at each end. There's also a spring attached to the button end (don't know if this is a change). You must have inspired them, Tool Using Animal!

author
moosetooth (author)chrisbaker2011-09-24

I have several of this type that quit working. The circuit board that the leds are on are pretty inaccessible so other than scratch the contact with a pen knife I can't do much with it. It's a shame cuz I really liked them when they worked.

author
tinkerinaround (author)2008-11-28

Advance Auto parts has these flashlights for $2 each. Test them all b4 buying, some have good(bright) LEDs, some don't. Try adding hot glue to the LED side of the board for shock protection. I've scavenged the push button switch from several of these.

author
thelightoflinux (author)2008-09-16

I just bought two of these at Big Lots. They came in a two pack for seven bucks. One of them is kinda crappy, but the other works pretty .I'm gonna try this on my bad one later.

author
grayelf (author)2008-01-23

Got a light like this for free...hardly worked at all. Battery insertion diagram on interior was actually wrong. Loose parts, but I never could figure out what was wrong. My circuit board was also different from the one pictured here. Actually burned a good sized blister into my finger from the current heating up the spring...got pissed and gave it to a friend. He got it working and thinks it is great.

author
Yerboogieman (author)2007-12-07

plus so durable and stuff but the guts dont look the same

author
Yerboogieman (author)2007-12-07

i liked mine so much and it lasted so long bought 9 of them

author
calculusrunner (author)2007-01-03

I have this same flashlight that I got from www.fifthunit.com a few weeks ago. They had a special for 2/$5 with free shipping. The site has some surprisingly high quality flashlights from China and such (you still get what you pay for, but its on the higher end of the cheapos). Mine had a spring at the top as well so I don't have this problem, but it looks like the solder might break loose so I'll have to keep this in mind.

author
unjust (author)2006-11-28

good hack. now lets see it with a few high output leds swapped in ;) (i'm actually workign on that, but having time issues atm)

author
GadgetmanKen (author)2006-11-27

Oh, and I originally wanted the ones like that in camo but they were sold out. Got a rain check, tho.

author
GadgetmanKen (author)2006-11-27

I have one of those too, with the same problem. I thought it was the contact spring at the bottom, because it was flimsy. But, I tried the nut thing with no results. After close examination, I noticed my circuit board was different than yous a little. The circuit board in mine just had an outer ring on the circuit board for I guess the ground and all the positive ends were wired to the center glob via the leads. And after closer examination I noticed that a couple of the ground side leads were a tad bit longer than the others. Maybe a couple cm. So I bent them over. Couldn't find my side cuts. DooH! Anyway when I screwed the hex grounding ring back in, I think I screwed it tighter than it was, but now does not flicker or shut off. Don't know if the longer leads were not making good contact or the hex ground ring. Nothing worse than a flashlight that won't stay on, or flicker. Its a great BRIGHT little flashlight. oh, and inexpensive too. I'm getting several more.

author
meddler (author)2006-11-24

Good idea, i bought a small light like this from an army surplus store and it doesen't work at all, maby this is the reason? Of corse it doesen't matter anymore since i threw it away....

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