Fixing a faulty battery PIR light that was draining the batteries fast. 

I’m not in the electronics business at all but I am totally fascinated by watching Clive and what he does explains it so well many many thanks as somebody says when it pops up on my phone and notification that you’ve done a new video it’s like where hey this is going to be a good day

15:36: “This should hopefully slide in here. Let’s try it for size. Is it gonna fit? Is it gonna fit? Is it gonna fit?...it fits!” A common phrase said by satisfied Bad Dragon customers.

For those wondering about the brick... It was an april fools day product that was released by bad dragon for only 24 hours back in 2018. That same day you could also get a solid silicone fidget spinner (without any bearings).

15:30 If not for the video, the endorsement of Bad Dragon followed by "is it going to fit?" would come across very differently.

I really enjoy these fix-it type videos. Always learning something new.

It's difficult not to love these fix-it videos. I learn something new every time.

Yes! I had an old fashioned alarm clock that I decided needed a small modernisation to rechargeable batteries. I used a USB Li-po charger module from eBay and connected that up to the battery. It worked great except it needed charging every month! Eventually I decided to dig up this rabbit hole and monitored the leakage current while heating up each component with a soldering iron. As soon as I touched the MLC capacitor, the current changed wildly. Now it lasts multiple months between charges :)

I love waking up a 4am and seeing a new video from Clive!

"Reflections on solder connections" - my favourite jazz track

Clive - 1~ landfill - 0 Great result :-)

These are the kinds of videos that makes me glad RU-vid is a thing. Glad to be able to see how to fix these devices and products.

Huh, this is relevant to my interests as I have a PIR that's draining. Amazing what you can learn here.

Hehe @bigclivedotcom, when I saw you start drawing a capacitor I could only remember my brother's attempt at building a very high voltage one to increase spark distance with the use of one of the high voltage transformers from tube TV's. He was experimenting with the thing when one of the isolation layers decided to fail and the driving circuitry started arcing furiously through it, which, due to the small hole it passed through made one hell of a noise. After having heard 6 really loud clicks being transferred through the central heating pipes it took about half a minute before my brother came down with a very disturbed look on his face and I asked if everything was ok, which he was, though he had ringing ears and ever since made sure to be able to have a kill switch near him instead of having to reach over the site of the experiment in question (which, with the arc-over incident could've been actually really dangerous).

Good job. Troubleshooting is a dying art it seems like these days, though it is just a LED lamp it furthers our knowledge and skills by making one think.

SMD capacitor cracking often happens when the individual board is separated from its original panel. It's very easy to flex the PCB and put undo strain on the part.

It's wonderful to me every time to see how different your soldering technique is from mine; my work on MRI image coils involved a lot of swapping out those cubic-millimeter SMD caps during circuit tuning, and I always soldered up the pads and then flowed one end down and then the other. I did have hot tweezers but those were really only useful for removing components. Most definitely hit those with 63/37 and a nice relaxed iron, though.

Nice one Clive. I had something similar back in the 80s. That issue was caused by a combination of thermal stress and flexing on the pwb when a harness connector was inserted in situ.

So educational for us traditional component users. And you fixed it using one.😃

I only wish I had your video's when I was younger. However your video's can and will help younger people. keep up the great work Clive

At 14:20 when I saw the wick for desoldering, I thought this was the Louis Rossmann channel.

Thanks. I experienced this exact problem not too long ago with my Swiss Micro DM42. It drained batteries in about 3 days. One capacitor had about a 1K resistance. A replacement electrolytic from my parts bin was too big to fit in the case. Swiss Micro promptly sent me a replacement part and my calculator has been working perfectly fine ever since.

I always wondered just how reliable those high-value SMD caps really are. I will definitely remember this problem, since it is not exactly an uncommon failure (and I seem to remember I've got a few battery powered PIR Leds in the shed, possibly with a similar drain issue! Thanks for a VERY useful bit of information, BC!

Hey Clive, soldering small SMD components with hot air is easy and fun. Place on the bench a scrap PCB, take hot air gun in your hand, start with desoldering components and then try to solder them back. Test different temperatures, air flows, nozzles, fluxes. It's easy to learn when there's no fear of damaging something, because it's scrap anyway.

"So totally wrong" - Such humility. Our politicians could well do with watching your vids Mr C! >;o)

Nice test and tear down. Very timely too: I have a diy pir under-cabinet lighting video coming up...using those free harbor freight flashlights.

something to look out for with those.. Thank you Clive.

A most interesting video indeed. Thanks for sharing. Best regards.

I've suffered through the exact problem you are detailng here. Ceramic smt caps are mechanically suseptible to shorting.

I am amazed that you managed to fix the pir light nay even locate the fault , you're a wizard. of electronics, thanks very interesting.

Great repair Thanks for sharing👍😀

Do you ever find your drawings weeks/months or years later and recognise what you were trying to demonstrate?

Back in the mid to late '90s about half of every day at work was taken up with replacing those capacitors in handheld computers because they'd failed in exactly this way.

Good fix Clive. Another option is to have some SMD tantalum caps on hand for tight areas where an electrolytic won’t fit.

Thanks for this great information and explanation

Repairing equipment is fun. Fixed a monitor with a broken backlight and a PSU with faulty lcd displays yesterday. Now I know how a LCD display works and that I can use a 10ohm resistor to Bypass a broken backlight. :)

Great fix..... cheers bigclive

As usual, very interesting video

I never thought I'd see the day that someone describes a surface mount component as "fairly chunky".

Brings new meaning to the phrase “shit a brick”

Fascinating indeed.

awesome video... thanks. they really should put labels on these little things as capacitance indicator.

9:33 something falls off the table (probably the circuit board he just set back down) Clive: 0 Fs given Great video as usual! Fixing things is cool. :)

Good repair

Very usefull video. Rob

Another great video. If I wasn't so far away I would send my "dead" emergency backup light fixture for diagnosis. Local guys want more than the item is to buy to look at it.Ah well, oh dear what a shame never mind. Great video.

These boards will be made in one large panel, maybe a dozen per panel. When this panel is 'broken out' into the smaller boards, stress or bending can cause an MLCC cap to crack. Then it's just a matter of time to catastrophic failure. I've seen boards being removed from a panel like peeling a banana. Result? a 30% failure rate.

Great a repair video lets see more and a good result very informative :-)

I was recovering a 1.0f capacitor from an old board (because I could). Made me remember the old 8 Mic wax/ paper caps in tv sets. By today's standards, they are almost a Leydon jar.

Awesome BigClive Classic

Just FYI. I had a whole batch of product that had one such capacitor problem and it turned out that the component glue and flux from the automated assembly process had conspired to make the PCB under a particular capacitor somewhat conductive, always the same cap and always the same cause. Remove the cap, clean underneath and replace (new cap BTW), all good again. lost count of how many we fixed but certainly many hundreds over an extended period.

Good video clime...

That was a trans-capacitor. It was transitioning to a resistor.

I got a selection of SMD capacitors of various sizes. My mind boggles how they make (and squeeze 100nF into) the absolutely miniscule 0201 sized versions. I know that they make transistors at the nanometre scale for ICs so it shouldn't really tax my brain in this way, but I guess it's because they're a tangible, physical thing you can hold and they're so small that losing track of it on your desk or dropping it would probably mean it's lost forever!

I see what they have done. I bought a pair of these and the one unit would switch off in 5 seconds and never return on. The other unit has remained in the porch for two years and works perfectly.

Seen quite a few of these caps fail now, often blowing fuses. Seen several times in Stannah stairlifts.

Reminds me of the tantalum capacitor problem that were widespread 25yrs ago, especially on PC motherboards.

I have 2 of very similar looking PIR lights(got from a Budget store in NL called action for 3 euro each!) But it eats through 3 AAA battery in weeks. I'm going to take it apart and try to fix it!

We used lots of these at my last company, and they do fail quite a lot when stressed from either heat or just flexing of the boards. Even more interesting when they're used in HV circuits as they can melt down or literally be blown clean off the board by the discharge when they fail.

Nice!

Thanks Clive this inspired me to look at an Aldi strip led PIR powered by 4 AA cells it only lasted a few days. It look as though they put a 3.3 V Zener to stabilise the voltage for the PIR this was fed b a 1K resistor it was drawing a constant 2.7m-A when the cells were new. Removing the zenner cut the consumption and it still works ok. I think the circuit was designed for power supply operation rather than batteries. Could this be the case?

Fascinating. I've been wondering how they make surface mount capacitors. It looks as if they are trading off size against reliability, and it isn't working out. Are the more expensive brands larger?

"It's always something. If it's not one thing, it's another."

Neat stuff. I always buy a tempered glass screen protector on my phones. :)

Always blame the capacitors before all else, that was the first lesson I learnt when I comes to troubleshooting power problems... Well that and how useful Bad Dragon "tools" are to technicians, because we work hard and play harder.

HAHA the infamous bad dragon brick. cheers bigclive great troubleshooting video

One "solution" to MLCC is to have two in series so if one shorts you still have one left before it shorts out. And also seen on EEV Blog it can be soldered to a seperate small pcb for holding the MLCC and the soldered to the board to prevent stress on it so it's decoupled from the main board

Rear window defroster repair material works for those surface mount caps.

I have a similar PIR LED light, which runs from 6 AAA cells, It came from Lidl, I fitted it in my front porch & it worked perfectly for about a year, on the original set of batteries, but it then started to repeatedly turn itself on & off about every five seconds, which ran the batteries down in a couple of days, but on fitting a new set of batteries its back to normal.

Very nice fix.. I just had an issue with a 1400 usd camera I own where the small SMD Cap like the one in your video here was went bad and took out my LM2676s-adj. Sadly I don't have the way to make the right repair do to not knowing what the CAP was. But I got a New LM2676 installed it and took a CAP from a different item that looks the same size installed it in the place of bad one and now my 1400 camera is working again. Sadly without a Schematic and not knowing what CAP I need I don't know how long that will keep it working... Odd thing is there was no signs of the cap being bad. I did all the Testing of the board till I found short to ground. Cap Removed That short went away kept testing till found the Power supply chip was also short to ground after removing a couple of other Diodes and a Inductor that I thought was bad found it was the 2676 after removing that no more short to ground... Put the other parts back on board. Ordered a NEW LM2676 and installing that. Sadly not knowing what CAp I needed I took a different item that was no good and removed a cap about same size from that installed in the camera. Tested the board for power it was back. Installed all the hardware back to the camera and put back in PTZ dome and now my Camera has been back in action for little over 24 hours now.

I've got two battery powered PIR's that are drawing way too much current and flattening the 3 x AAA batteries. Yet they both work OK. So by your measure I should look for a leaky C first eh? There's also a SMT electrolytic that has been replaced with a wired electrolytic (in both) ....!! I suppose it makes sense since it works, but what do you think of that: They do usually leak a bit of DC. I've dealt with surface mount BUT not really the fault finding/failure side of them. I'm aware of static damage especially to Transistor junctions. So I'll go for the caps first then. I enjoyed your videos. Unpretentious, very honest, and full of handy snippets. Thank you. Notes: Me a lifetime of "electronics" from valves on. A bit lazy now wrt surface mount as the eyesight isn't that good. These really are tiny. I just want a result! Rgds BjG

Lious Rossmann has another way to find a hotspot: Spray the board with high-purity IPA (which you have around anyway for cleaning boards) and look for where it evaporates fast.

I have had multilayer ceramic capacitor fail with flames. That was when I tried to use them at something like 18 V AC. Never again... As to the conductive material inside - somehow I had an impression that it might be palladium, but maybe that is only used in the tiny resistors. But I often try to figure out the RLC equivalent components in similar situations. The capacitance (and possible inductance) have frequency dependence. The resistance not so much. My component testers are limited to the common 100 and 120 Hz and 1, 10 and 100 kHz test frequencies. Beyond those, I can use my 1 MHz LCR bridge (if it likes to work -- I would need to clean all its myriad of dirty contacts) or get out my HP Q-meter. Mostly I pick up a few resistors and make a 50 ohm parallel set which should minimize stray inductance. Then I connect the component of interest in series with the 50 ohm assembly and use a VNA Mini to see what I can find. Oh, I sometimes have also tried what my phase angle meter can tell. It is limited to 13 MHz. In that respect, I probably could see the behavior with a sine wave signal and my oscilloscope. More than one way to push ahead, when I get interested enough.

Thanks for that small heart attack when i saw the brick!

i wonder if it got a static discharge "zap", that for sure kills them. I've seen it happen on tv's where the people zapped through to the side button board and it shorted a cap out down on the remote sensor/power led board at bottom of tv, they were directly connected then from there to the bigger boards.

The Bad Dragon brick is Big Clive approved, that's all I need to know, I off to go order one

Hey there Clive. You might try putting some Kapton tape over shiny components and targeting the tape with your FLIR.

I used to "fine tune" carbon comp-through hole resistors by filing away at the body of them with it connected to a ohm meter - it was pretty reliable too

Good morning

10:52 Sounds like someone learned that the hard way :3

Hi Clive, Great video as always. Just wondering what thermal camera you would recommend would like to get a good one but not sure what to buy. Many thanks.

I upgrade these types of lights with 18650s and a TP4056, maybe a buck converter if it isnt bright enough. Works very well

For all your rectal full-fill-ment?

Philipp does not need a lot of test equipment just give him a Marks A Lot. The B ended in an interesting spot on the board.

Hello Clive at 9.25 in on the video you show a component, and would I be right in saying the unit was a touch light box, it looked very like one I have just replaced in a lamp. They tend to blow quite often and wonder if you have done any videos in reverse engineering and figuring out what component really fails? If not it might be an interesting project vid. Many thanks enjoy all your videos.

hmm, I've recently started making some PCBs at work for use on drones and I've been thoroughly enjoying the availability of very small footprint 1uF mlc ceramic capacitors for power supply and decoupling circuitry. A minor revision may be in order :/

clive didn't the cap you added electrolyte do the same thing? in that car video???

Are you familiar with the Stanley Flashlight/battery bank? It seems to have a well known flaw where it starts draining battery too. Wondering if someone out there might have one to send to you for autopsy. I would like to find a fix for mine. It was very nice until it failed.

Copper end caps? I wish. Every SMT resistor and small cap that I've seen had steel end caps. The tiniest bit of magnetism on your tweezers will tombstone those things in an instant.

Clive I'm curious about what printer you use, the image quality looks really good.

Can anyone tell me which EEVblog video clive was refering to where the capacitor caught fire?

Go small cause bigger problems. At least when the old ones went faulty you got a decent bang and loads of paper inside and a nice bit of tin to cause other shorts until it stopped bouncing around. Well, some of the time anyway. But I like things that go bang!

I remember Daves videos your refereing to from eev blog channel @bigclivedotcom

You Do a Video about A2SHB MOSFET...!

Good job.... I had a teacher that was an electronics technician in the air force. And he had a jet that had radio problems. No matter what radio that he put in, it had troubles. He finally went to his co, and asked for help. And the officer in charge , handed him a can of polish. It seems that the final output capacitor was the inside of the case. And once it was polished, the radio worked... At least that is the story that the teacher told. All of this is to ask... Is there any way to make the case into a capacitor in the circuit? Or maybe part of the circuit board? As a school project I made a capacitor out of aluminium foil, and cardboard. Thanks for sharing your videos.

Definitely not the first time I've seen MLCC failure -- don't get me wrong, I still use them, because the benefits outweigh the potential of failures -- but man, it is difficult to ascertain _WHY_ they failed. Physical/thermal stress-induced fractures are probably reason #1, but I've also seen improper flux-cleansing methods cause leakage problems. I do have to wonder whether some MLCC manufacturers tend to push the voltage rating limits of their components.

"rectal fulfillment" thats one way to put it 😂

"It's time to explore the circuitry." *clicks "Like"*

epic plug plug 10/10

so how many LED units that are hardwired in may possibly have this issue? they don't have batteries so power usage would probably go unnoticed unless it acted strange or just straight burned itself out.

which P-channel mosfet goes with A2SHB ?