LED Flashlights (StreamLight) - Page 1
Forum section: electronics / beginners

author: thorthor
author_rank: Newbie
timestamp: October 25, 2020, 12:22:58 pm
content: Hello my names Kyle was wondering if someone could help me identify the part in the red circle in the image its part of a flashlight it had gotten broken when I decided to take it apart just to have a look inside(I've come to regret that decision slightly lets just say that wasn'tthe only thing that broke first time I've ever broken multiple parts in the same teardown) haha anyways im just starting to get into electronics for the most part I'm pretty sure its a diode but not 100% whish is why I'm asking i want to fix the flashlight cause its my EDC. I also have a vape mod that won't charge cause the iron inductor broke from being dropped(I can take a pic and post of it also if needed) i just don't know how to identify what size etc to replace with.

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 25, 2020, 01:26:41 pm
content: Your wall of text is barley readable at all. Please use a dot to finish a sentence. This will increase the chance for you to get answers.That part you marked is an electrolytic capacitor. The marking "476" means47* 10^-6F47* 10^6pF = 47µF. Also the silkscreen marking C2 indicates that that's a capacitor. The voltage rating is unknown, but as it's a battery flashlight the voltage is probably 6.3V.About the size: You need to measure it and lookup matching parts on online stores. One assumption would be 0603. That is 0.06in x 0.03in.But my guess is that this is not the defect of the flashlight. In flashlights I would more expect bad contacts or cold solder joints (broken due to vibration).Edit:Thanks to ledtester who pointed me to my mistake about the calculation.

author: thorthor
author_rank: Newbie
timestamp: October 25, 2020, 03:22:13 pm
content: Thank you for your response. But oh boy can't help but to laugh at myself for not even thinking to look at the silkscreen. But ill have to search new ones see what they look like. This one looks like a small chunk is missing from the bottom. The badly soldered side was a broken connection, but the light continued to partially work with it unconnected(full brightness only, no strobe or minimum bright). ..Sorry about the grammar. I'm using my phone and got use to not properly using it, that and I'm not any good at remembering proper placement etc.

author: thorthor
author_rank: Newbie
timestamp: October 25, 2020, 03:32:53 pm
content: The flashlight uses 2 Cr123 3v lithium. So would it still be a 6.3v cap. Sorry just not sure what the tolerances etc usually would be.

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 25, 2020, 04:06:53 pm
content: The tolerance usually doesn't matter. Especially for this application. The J actually indicates the voltage of 6.3V (example data sheet:https://www.mouser.de/datasheet/2/40/AVX-F97-HT3-1313840.pdf).You might check also the L+ and L- connections. I think that might be the terminals from the inductor on the back-side of the PCB. The L+ one looks a bit bad soldered. As it is a double-sided PCB the soldering might be OK. It's hard to see in the picture.Unfortunately I don't know the reason for the failure. It uses a single button for the modes, on/off? In that case the cap might be the reason. As the chip needs some energy to store the current mode while it is switched off for a short time. If you can wire up the lamp that allows you to run the lamp disassembled you might attach a different cap with wires for to see if that helps.You should use less solder and more flux if you work with this small packages. But that still looks ok!

author: thorthor
author_rank: Newbie
timestamp: April 27, 2021, 06:42:18 am
content: Thank you for the assistance. I managed to solder the end of that cap back down and the light started working normally again, atleast that was until it stopped working altogether. I got a replacement under warranty, I guess it was a common issue. Sorry for the super late response had life get in my way.

author: ledtester
author_rank: Super Contributor
timestamp: April 27, 2021, 12:18:23 pm
content: Quote from: Twoflower on October 25, 2020, 01:26:41 pmI believe the capacitance is measured in picofarads, so "476" means47* 10^6pF. In this case it also results in 47 uF, but "477" would mean 47*10^7 pF = 470 uF, not 47 * 10^-7 F = 4.7 uF.

author: Twoflower
author_rank: Frequent Contributor
timestamp: April 27, 2021, 12:25:28 pm
content: You're absolute right! It seems I had not enough coffee that time.

author: Zero999
author_rank: Super Contributor
timestamp: April 28, 2021, 10:13:22 am
content: Quote from: thorthor on October 25, 2020, 03:32:53 pmI would hope it's rated to at least 10V, since it's appears to be a tantalum capacitor, which is highly likely to fail catastrophically, if continiously operated too close to the maximum rating.

author: thorthor
author_rank: Newbie
timestamp: April 29, 2021, 07:07:29 am
content: Im assuming you're correct cause that cap failed 1 side lifted up(possibly a chunk came off couldn't really tell at the time). I managed to solder it down which fixed it so all modes worked, it worked great for about 6ish weeks then it repeated I couldn't cycle modes(max only). So I got it replaced. ....... Fun side note StreamLight has repair centers. I much rather would've supported a local repair/retail over ordering online.

author: M.Zohaib Usman
author_rank: Unknown
timestamp: April 30, 2021, 08:54:43 pm
content: Quote from: Twoflower on April 27, 2021, 12:25:28 pmYou gotta press the Quote button to reply to someone specifically, not the Reply button.

author: Twoflower
author_rank: Frequent Contributor
timestamp: May 01, 2021, 06:22:41 am
content: I usually don‘t use the quote button if i post a diect reply to the previous message. Only in case a specific part of the message. And many people seem to do the same.