LED safety triangle -repair/teardown

This is a quick diagnosis and repair (and curiosity teardown while I'm at it) of a flashing LED safety thing a friend-of-a-friend asked me to try and fix.
Turned out to be one of the most common types of failure and a very easy repair
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This isn't the only way to do it.
It's probably not the best way to do it.
But it's how I did it.

[@Ernzt8]

"I fixed it, let's take it apart" :) Reminds me of my father, who removed half the car dashboard while standing in a traffic jam - just to see how it fitted together

[@Dime_Bar]

I like it when they're easy as well.

[@mikepanchaud1]

Hopefully a helpful, constructive comment. When screwing into plastic, turn anticlockwise til it clicks to find the original thread. Just forcing it in will eventually damage and wear out the plastic. In fact, find the thread just as you would with a metal thread!

[@petertryndoch8857]

Sometime I find the plastic on either side of the positive terminal prevents the battery from making contact. And some batteries have a slightly longer positive nub than others. Bending the positive terminal out slightly fixes the problem.

[@JSGregg]

Thought it was weird at first to see a PNP being used in an NPN configuration, but I guess it saves ones resistor plus limits the current.

[@frankowalker4662]

I imagine it's like a 556 blob chip. One half is a latching switch, the other half is an LED flasher. (?)

[@MasterBakerVideos]

I've had one of those on my truck for the last 20 years. Finally took it inside to see if I could use it for something. Not uncommon for the tabs to build up a thin oxide coating and stop conductivity. I suspect a 555 timer and resistor in the blob.

[@therealjammit]

Not necessarily a 555. A CMOS microcontroller that's generic but can be programmed at the factory is cheaper in bulk. The blob chip is probably the same one used in musical greeting cards. The only "note" this one plays is a repeating "blip".

[@Multi-Skill-Bill]

How many times the easy fix is the most fun fix. Now take it apart and not worry about anything being broken LOL.

[@jstro-hobbytech]

It's doing some sort of highside switching with the glop oscillator and pnp transistor so the leds stay in sync. I suspect it's an all in one 555 with super tiny smd resistors and cap. Be cool to peel it apart and microscope it haha. I suspect heating the resin would destroy it though. Cool little circuit though. Could've been done with just an opamp too. Someone had to design that gloptop and one has to wonder if they really saved that much money hahaha. I'm overthinking and probably completely wrong haha. Cool vid

[@markfergerson2145]

If it was mine I would be sorely tempted to put twelve volts to it to see if it would still work. It’s barely possible the blob contains a zener or similar regulator. Wait, I didn’t notice that transistor’s c-e rating. Can it handle twelve volts? Also, why is that diode where it is, and why is it in the circuit at all? What kind of diode is it?

[@Elnufo]

I would have expected to see at least a timing capacitor on the back of that circuitboard. oh well, cant have it all. Cheers

[@snakezdewiggle6084]

OH NO .! Repairs that Autofix.! Is this Dog River.? Where's Hank, anybody seen Hank.... Where's the pile of lumber ? Ahhhhhhhhhn

[@jstro-hobbytech]

That's hilarious. A similar thing happened to me today. I bought a 55 inch lg 3d tv from a buddy who paid like 3600 for it 9 years ago. I got it for 60 bucks. The remote was broken since he bought it and it's one of those LG smart remotes. I fixed it in 2 seconds. Hahaha. He had it for years and put up with the broken remote.

[@michaeltempsch5282]

He could probably have gotten a matching remote from like AliExpress for under $5

[@retireeelectronics2649]

Dam easy fix, tear it apart (-:

[@RottnRobbie]

So, um ... did nobody else notice the small circuit board has "3V IN" screened on the upper left corner (3:50). Not to mention the outline for another transistor, an unknown component between it and the screw, plus outlines for what look like 2 large-ish polarized 2-pin components, one of which is marked "TORCH"? No curiosity, I guess ...

[@pileofstuff]

I noticed it, but that's not where the batteries were connected in this application.

[@RottnRobbie]

​@@pileofstuffYah, I get that. But Clive would've at least pointed it out, and most likely commented along the lines of "I guess it's a universal circuit board, used in several applications". Of course, he also would have noted that all the wires, both + and -, are black. We can't all be Clive, and I generally love your content - but still, I'm _ever so slightly_ disappointed that you didn't even mention the anomolies.

[@pileofstuff]

@@RottnRobbie There's much more that ends up on the "cutting room floor" than ends up in the final video. If I left everything in the video would be an hour long.

[@TheUnofficialMaker]

not much to see here.

[@pileofstuff]

Much less than I expected.