Everybody has to start somewhere... What are some of your memorable oops moments with flashlights, general lighting, or electronics/modding in general? I'll go first.
My first attempt at reflowing an led was with the GBGB S1 clone. I spent probably a good hour disassembling the light, removing the old led, and cleaning the surface. I had everything set up for the actual reflow... Nichia 119, helping hands, heat gun, solder paste. After verifying the anode and cathode locations, I placed the led onto the thermal paste, pressed down, and started applying heat from beneath the mcpcb.
After a good 30-60 seconds that seemed like forever, the solder paste started to melt, but the led seemed slightly off-center. I grabbed the tweezers and attempted to nudge it lightly back into position. Well, I applied too much force and knocked the led clean off the mcpcb... down into the heat gun.
I turned off the heat gun, shook it around, and searched the entire area. That little led was never to be seen again.
Fortunately the body forgets pain, unfortunately so also does the mind. This is why a failure to document failure will lead to it’s repetition. I can’t remember my first flop but I’m always loading LEDs wrong way round on the star so imagine my consternation when my latest attempt (a quad Nichia) informed me of my error by refusing to light. Instead, the 10440 test cell got very warm very quickly and I had to determine which one I’d laid across the pads instead of along them. My go to source for determining this was one of my last builds which I knew to be wrong so finding the led that matched this one gave me my culprit. Why can’t they just put a + on them? And not some microdot like Cree uses or a single corner dot that still doesn’t tell you which edge is positive. Aaaaargh!
hmmm memorable OOPS moment………I was drunk and it resulted in “honey i’m pregnant”
oh, with flashlights! reflowing a OSRAM black IR LED and forgot if I put it on there correct. Heated it up again and took it off. Reflowed it again. I obviously had a brain fart because I remembered which way was + and - and realized I did it wrong so I took it off again. 3rd times a charm. The notch goes toward the negative. I won’t forget it now.
I once dead shorted the leads of a 25c 6s lipo pack a few inches in front of my face as I was soldering new connectors and the contacts exploded into vapor. Luckily nothing got in my eyes. I actually screamed involuntarily for a second when it happened.
Two years ago I did my very first led reflow, I attached an aluminium block to a 12V solder iron for that. Normally my hands aee not shaky at all, must be too much coffee.. I was careless enough to put it on camera (and even post it on BLF, I must be a masochist):
I had one last night. Cleaning up the silicone on the die of an LED I just dedomed I scraped off the wire side without thinking. Followed shortly by a four letter word.
But of recent vintage and a big OOPS! moment happened while mounting a Luminus SBT-70 emitter. This is a $45 emitter! I pressed down on the flat glass window to squeeze out excess thermal adhesive under the star and CRACK! the little glass window shattered! It’s unbelievably thin. Go for two oopsies in a row? While soldering the leads on the now de-domed big die my soldering iron slipped and crashed into the beautiful suspended bridge pattern of bond wires! This ended up the demise of a beautiful and favorite very expensive emitter.
The most beautiful emitter created, round die and all!
And after a couple of back-to-back oopsies…. not so much
Being a glutton for punishment, I’m about to embark on a build utilizing 3 of these beauties! Wish me luck! :bigsmile:
Most recent one was fumbling around and dropping a reflector into a light with dedomed led and knocking the led/bond wires with the reflector.
I’ve also ended up with the blue mtg2. I tried to ‘peel’ off the dome. Thing is once you see part of the phosphor come off you know the led will never be good so I kept going and ended up with a perfectly dedomed de-phosphored mtg2 that made lotsa blue light.
When doing certain builds I sometimes have a habit of making a dead short and melt the contact springs.
The list goes on. I’m surprised I still get into this hobby.
That’s an interesting pic DBCstm. My eyes aren’t too good so I’ve never seen the sbt-70 so clearly. Makes me wonder why they use bond “wires”? Why couldn’t they use a bit of flat bar or something like the traces on PCB’s?
Then you might also like to know that the die is an actual circle. It does not extend under those golden panels. I ended up completely disassembling this one, and the silicon wafer is round. I have it separated from the rest of the emitter and it’s a thin round yellow disc.
(I tend to stay in class til the bell rings when the lesson is $45 a pop!)
I had a head machined up for a light finished but deemed the driver hole had to go a little deeper. Machined the hole deeper and took it outside. Hmm. Why does the masking tape look like this?
Yep, I had machined through into a cooling fin. I now had a two piece head.
I hate when that happens. I had similar experiences working on 1405 pills. None of them were as heartbreaking as that probably was since it just means one of my 1405’s can infinitely adjust and the other has a “unique” flange.
for all my oops! moments. It would freeze up. Forever. Last flashlight related oops! (D/A as I call myself) incident was leaving the batteries in while attempting to re-solder an led in a 3C Utilitech. Luckily I got it 50% off. Did I just say that? Luckily? I didn’t go so far as to document it as some of you have. I especially like the close up pics. Too bad that ain’t on video. You could do it in “super-slow-mo-macro agony of defeat” mode.
My motto is: If it ain’t broke……………………….I’ll break it!
@ djozz - sorry, but I couldn’t help laughing at that video…
My recent oops; I dusted off last years DIY build (Hand Mortar) to take some throw readings.
I whacked some fresh cells in, but would only get a brief flicker when I hit the switch….
I figured the driver may have failed, & after pulling the entire thing apart, & removing the driver, I remembered that the cells needed to go in ‘backwards’, with + towards the rear of the light.
There was nothing wrong with it…… :zipper_mouth_face:
Hah Djozz, that video so perfectly sums up my first few reflow experiences! Awesome vid
Guys, hands off the espresso machine if a reflow needs to happen
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My most recent oops involved frying 3 brand new xml2s first time I hooked them up to test.
Was using my iCharger to supply power, it does a decent job of imitating a variable power supply most of the time. In the motor test mode it’s basically a 1000w variable switch more power supply so for really high power led stuff it comes in quite handy.
But…if the connection is broken for any reason the supply has a tendency to stop controlling voltage and charges it’s internal power caps to some higher value. If you then reconnect the circuit without bleeding off the high voltage on the caps it WILL kill any led you have hooked up to it. Or 3 in my case, not even a flash…instant emitter demise :_(
I really need to get a proper variable power supply to avoid this happening again in the future.
As a kid I used to mess about with all sorts of electrical stuff, pulling all sorts of electrical stuff apart to see how it worked,was not always so good at getting it back together, much to the annoyance of some of the family
Anyway one day I’d been playing with some 12 volt bulbs I’d found, trying to see how bright I could get then, after much playing with various batteries I still wasn’t happy with their light output, so in a flash of inspiration I decided more power was needed :bigsmile:
So I wired one straight into the the mains (240VAC) with some speaker wire
It was amazing bright, briefly, very briefly followed by a big bang, lots of smoke and melting cables
