Fixing a faulty LSPA7 smart plug (XiangHeWang)

This seems to be a very common WiFi smart plug with multi-country socket options. As with most of these things it has its weaknesses, and this one has failed.
The fix is simple enough, but you must be aware that these units are not held together with screws, so the case will never be as strong as it was before the fix, and there is a risk of exposing live connections if it comes apart while being unplugged.
This circuit is ALL live at mains voltage when powered, so take suitable precautions when testing it while open. Complacency is your worst enemy here, and it's not uncommon for people to slip up and grab it to pull things like this out of the socket/receptacle while they're still powered. That results in a very harsh safety lesson.
At no point did I handle this unit directly while it was live.
For the repair you will need a beefy soldering iron for those pesky high thermal mass power pins and tracks. Or just take your time and allow the soldering iron to recover between each use.
If the solder refuses to suck out of the capacitor holes then you can resort to the toothpick technique to clean them. Get a very sharp wooden toothpick, melt the solder and shove the toothpick into the hole to displace the solder. Once cooled, the toothpick will come out easily leaving room for the leads of the new capacitor.
Double check the orientation of the capacitor, as electrolytics are a polarised component and may pressurise and pop if installed the wrong way round. If that happens then just stick another in the right way round after cleaning any explosion-residue off the PCB.
I'd expect the capacitor value to be the same for other countries - 470uF 10V. It's important to use one rated for high frequency use, sometimes referred to as low ESR. (Low Equivalent Series Resistance). The one I used was from a UK component supplier called CPC (Farnell) and had the stock code CA08306. Try to use a proper component supplier, as eBay sells off-spec factory reject junk.
Although apparently rated for 16A, I would never trust such a tiny relay with that current. 5A would be a much safer rating. That means it's fine for most loads, but not things like big heaters.
It should not be used with loads that have huge inrush current, as they may cause the contacts to weld. That means the current spike causes the contacts to stick together. They can sometimes be released with a sharp tap on a hard surface.
The power monitoring facility was a nice surprise for such a compact unit. It uses a dedicated BL0937 chip that is designed for that function.
For the firmware reflashing posse - the chip is marked Beken BK7231T0N32
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- www.bigclive.c...
This also keeps the channel independent of KZbin's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators

[@peter.stimpel]

Thanks for creating lengthier videos, Clive. Appreciate this kind of videos quite much. TikTokstyle shorts are fluff

[@lImbus924]

Regarding "flicking off" the old solder blob: I actually intentionally drop parts like these from 10cm and less. In my experience it works quite well to also clear solder from small and big holes .

[@Loscha]

I use the "heat and bash" method. Just bash the thing against the table to dislodge the molten solder onto the bench.

[@pault6533]

I've also used a stainless steel paperclip to physically move the solder out of the hole while molten. Or a toothpick. Solder doesn't stick to these things. I always break something when I flick.

[@hugegamer5988]

Percussive repair has been used since the beginning of time and repairs themselves.

[@d00dEEE]

@@Loscha Yeah, I'm a basher, too.

[@lImbus924]

@@pault6533 I don't recall who recommended this to me/us, maybe BigClive, or maybe AvE: I have bought a set of needles (actually hollow needles, like syringe needles) of various sizes, stainless, that can be inserted into a solder hole, sometimes even additionally to/over/around the component lead. Insert while hot and retract when cold, this sometimes makes it easy to remove/unsolder a component, specially if you want to keep/reuse it later and need the leads.

[@RossReedstrom]

One day, bigclive, one day earlier and you would have saved me screwing up my own fix of a similar "smart" switch. Same issue, same part value, though mine was more obvious: the 470 uF cap had blown its can completely: at first I thought it was mounted "high" to get away from the heat of the inductor, then I realized that that wasn't insulating tubing over the leads, it was the cardboard guts of the cap. So far so good. Where I screwed up was trying to pull the plastic part off the power leads, thinking it was a friction fit, rather than desoldering it like you did. Won't budge, so I broke out the heat gun. Yup, still wont budge, but now it's not even close to "flat". So now that you've shown me the way, I'll de-solder it and fix it. I guess I'll have to find an alternate packaging solution: perhaps wire a cord to it and put a big old "gland" over the spicy bits.

[@ColinWatters]

Just for new electronic engineers... Electrolytic capacitors can have a rated life as low as 2000 hours at max operating temperature. That's just 83 days. Provided other parameters aren't exceeded, the life expectancy doubles for every 10C reduction in temperature. So using good makes of capacitors with a higher temperature rating and keeping them cool is essential or you will have a lot of warranty returns. The Panasonic capacitor Clive used is a pretty good make.

[@User-w7ckl]

Why is that? Does the electrolyte inside dry?

[@ColinWatters]

@@User-w7ckl Yes, the electrolyte either evaporates or leaks. As it dries out the Equivalent Series Resistance increases and this can cause increased heating and accelerates the problem. In extreme cases you get gasses building up inside which can bulge or burst the safety vent (X on the top of aluminium types).

[@MarkoVukovic0]

Excellent info and advice, thank you!

[@tec4303]

How can I design my circuits to avoid this? What can I do if I need a 20 year lifespan?

[@ColinWatters]

@tec4303 If you must use electrolytic capacitors then select a good make and make sure they operate in a cool environment. 20 years = 175,000 hours. Some capacitors are rated for 5000 hours at 105C. So they should last 10,000 hours @ 95C; 20,000 hours @ 85C; 40,000 hours @ 75C; 80,000 hours @ 65C, 160,000 hours at 55C. So you need adequate cooling to achieve long life. Best advice is to consult the manufacturers. Things like the ripple current also have an effect.

[@nightcatarts]

Yay, I just bought two of these a day ago (differently branded, & for Zigbee, but they look exactly the same). I'll only be using them to charge a tablet every so often, so with any luck they won't fail on me. Some epoxy around the edge once the cap is replaced should make them plenty solid though.

[@monteceitomoocher]

Nice easy repair, those little caps take a real beating at those switching frequencies, only slight criticism, should've swabbed the burnt flux off with some alcohol and a q tip.

[@bigclivedotcom]

I'm cautious about using isopropanol near switches and relays. If it penetrates in it can carry flux residue to contacts and cause issues. I made a video last year where I dug out very old PCBs with the flux residue still on them and they had no signs of corrosion.

[@keithking1985]

He was me wondering "what the hell is this for" till i saw the WiFi module 😅

[@tactileslut]

This one was rough, Clive. That first 400v capacitor was ready to bite your finger. Another finger strayed pretty close to the iron. You didn't power it up with clip leads before resoldering those power pins. Glad it seems to have had just the one problem.

[@bigclivedotcom]

Thankfully it takes total failure for the main input capacitor to hold a charge. The slight glow on the blue LED showed the buck regulator was still running. I should have made a show of discharging the cap though.

[@moo4983]

I've found these plugs work decently until the relay contacts start to stick. I use them to turn off appliances overnight so they're only ever exposed to standby current at the time but I find it necessary to give them a little jolt from time to time.

[@muxerbaker4638]

Monday night, I was searching *everywhere* for the one of these I took apart, as I need the WiFi chip ID. I have about three of these not taken apart, and since they don't go back together properly, don't want to open another. I was really hoping Clive would say it in the video! Does anyone know the ID of the WiFi module?

[@bigclivedotcom]

Beken BK7231T0N32

[@309electronics5]

​@@bigclivedotcom now its totally logical to have that because tuya (the main/mass producer of these wifi iot modules (with their secret sauce)) switched to beken and realtek a few years ago. There are alternative firmwares for them but yeah just some info and backstory why these modules are in almost every smart iot device

[@gedtoon6451]

Great video. A high tech product brought down by a cheap capacitor! I have seen these smart plugs from several vendors, do you think they all come from the same factory?

[@bigclivedotcom]

Possibly mass cloning or just custom branding.

[@gordonbaron9868]

Gordon here, update, I can confirm i changed the caps in 9 of my duff plugs and they all worked as they should, thanks Clive

[@rpdom]

I'd like to see what that cap shows as on a meter, both capacitance and ESR. Also, what rating did the relay claim?

[@bigclivedotcom]

I stuck the failed cap into a component tester and it showed up as a diode with a capacitance of zero for some reason.

[@pault6533]

@@bigclivedotcom Dried up then.

[@amorphuc]

Thanks Big Clive. I like the "proper" fix it videos. I think what's cool about these is watching your techniques and commentary throughout. More gold there in tips and actual working knowledge.

[@mistermeaargee2670]

As soon as the video started, I said “It’s the damned capacitor, Clive!”. I’ve repaired so many of these dinky little power supplies. See you tomorrow for the stream.

[@phonotical]

Reading that comment first the whole time I was thinking he was about to get a shock 🤣

[@Amberlynn_Reid]

Before the video was even posted I knew it was a capacitor

[@erikkovacs3097]

30 years ago, as a child, I woke from a fever dream and screamed "It's the capacitor!".

[@ArlenMoulton2]

@@erikkovacs3097 25 years before I was even born I had a moment of clarity and blurted out "it's the capacitor!" without understanding the context or world-changing significance!

[@Ed19601]

I work in a hospital and whenever one of the med students has a problem with the diagnosis i say: "it's the capacitor"

[@CBdesigns70]

Most of my smart IOT devices are liberated from the chinese by reflashing the onboard esp or tuya chips with Tasmota or openbeken, they are now local Lan & mqtt controlled instead of the "Internet required Cloud" and are better to use. Multi relay devices are all on or all off by default configuration but once liberated you can control individual relays and have greater control over what is connected. I say goodnight to Alexa and it turns lights on and off as I go to bed (yup lazy as can be)

[@chrishartley1210]

Liberated from the Chinese, and then you use Alexa.😂😂😂😂

[@TheDZHEX]

dude, can you make a tutorial (series) for that sort of thing? Being able to actually use hardware that's been discontinued by the manufacturer and the requirement of their proprietary cloud service has rendered them useless, would be incredibly useful for consumer freedom and reducing waste. ... maybe big clive or perhaps Louis Rossmann can do that, if they realize it's an option - Louis would definitely love it.

[@-vermin-]

@@TheDZHEX Tutorials already exist. search for "flash smart plug".

[@cuteraptor42]

@@TheDZHEXflashing a no-cloud firmware like tasmota on any of these esp is quite easy once you figure out the pinning of the chip yourself or if you find it in the numerous documentation pages made by the community

[@markbooth3066]

While most esp8266/esp32 devices, and older Tuya devices are easily flashable with Tasmota or ESPHome (which I prefer for Home Assistant use since you don't need a separate mqtt broker) and many even have programming headers, newer Tuya devices like the LSPA7 use a proprietary microcontroller module that can't be flashed yet, even if you can get at the module. It's a shame really because these are cheap (I have a few) and unobtrusive, compared to something like a sonoff.

[@chatrkat]

Fun little repair for a New Year’s Day. I’ve been soldering since I was around 10 years old I am 65 now, but when I use an iron that close to my fingers while slightly struggling to remove something, it almost always guarantees a burn. And a few well chosen words to confirm the mistake.

[@mySeaPrince_]

You could coat the part of the iron or your fingers with high temperature silicon.. reduces the ouchy heat 😻

[@mySeaPrince_]

Do you remember the Everyday Electronics magazine and the Ladybird book 'Making a Transistor Radio' ... and Camberwell Green. Happy Time's 😻

[@chatrkat]

@@mySeaPrince_ 😹👍🏻

[@manuellongo4365]

@@mySeaPrince_Fond memories......sigh

[@mySeaPrince_]

I've just remembered.. There's a KZbin channel.. 'Dave Knowles' .. on which there are Jack Hargreaves films .. he was on 'How' the TV programme answering questions. Something nice while the weather is.. wet!

[@SirBoden]

Strangely, this actually will defrost your car 😋

[@tin2001]

Yep. Stick it into the socket nearest to your car, program it for an appropriate time before you leave for work - I recommend about 1 hour before the usual departure time.... Then simply run an extension lead out of this device to a heater you've placed inside the car.

[@linuxgreybeard9945]

Sorry Clive, got to give you an A- for the flick technique. To get an A+, you need to bang either the PCB or your wrist on the workbench. The rapid deceleration creates a whiplash effect which in turn, removes more solder.

[@Damien.D]

Heating the pad or the pin and banging the pcb on the bench is my favorite way to get rid of excess solder ;) Nice and clean repair. Very profitable too, doesn't cost much in time or component, and save a thing that surely cost something.

[@AttilaAsztalos]

Small note: electrolytic capacitors failing in modern gear (as in, not in old 80's stuff) do so because the OEM failed to install a LOW ESR capacitor in a role that involved fast switching. See, any electrolytic capacitor is fine with the job of smoothing a mains powered 50-60Hz ripple. As in, a mere few dozen times per second. But modern electronics use switching power supplies that empty and refill those electrolytic caps many dozens or hundreds of THOUSANDS of time per second - and at that rate, the ESR (equivalent series resistance) of the cap DOES matter, with all that current sloshing in and out boiling the capacitor's electrolyte through sheer resistive losses if it ISN'T a low ESR cap. So... companies cheap out, or just doesn't care, cap says "uh-oh, I'm toast", product dies. Everyone goes surprised Pikachu face except the engineers who go "oh, FFS..."

[@TeddieBean]

Surprised Pikachu face 😂🤣

[@markevans2294]

It's a simple matter of cost saving on the part of the OEM. Especially when the branding is "Randomly generated name from Shenzhen".

[@ralphj4012]

Unfortunately, you see this even in products produced by so-called reputable manufacturers. A reliable design would use a two-stage filter and surge suppress. I'm not sure whether this is manufacturers ensuring their products only last a few years or bowing to consumerism or just bad design (or a combination).

[@MrDuncl]

@@ralphj4012 Surprisingly Panasonic DVD recorders don't use Panasonic capacitors but some type that is notorious for failing after about eight years. Buy a faulty one and there is a big chance that some capacitors have blown their tops.

[@rfmerrill]

I've actually found leaving a little bit of the end with solder on it makes solder wick work a bit better because it will wet immediately. I've also generally found it's not always best to have the wick between your iron and the joint--in fact I often flow the joint with my iron and _then_ bring the wick (with flux on) to it and try to touch the iron to both at the same time. Iron to dry wick does not make very good thermal contact and you'll burn up all the flux on it which will blacken your iron tip and make the thermal contact even worse! To put it another way: having some solder on the iron and/or the wick can counter-intuitively help remove solder because it provides a more instant thermal contact. Additionally, sometimes it makes sense to have the iron on the joint instead of (or in addition to) the wick, depending on how much heat the joint needs.

[@davelowets]

Yep.. I agree. Solder wick braid takes a little practice to get proficient with it. Sticking the end of the braid into a tin of paste Flux helps with those stubborn situations also..

[@denisohbrien]

my best tip with braid/wick is to add more flux, the pen type dispensers work really well here. more flux more better.

[@JohnDoe-bd5sz]

Also use a braid that is the correct size...The one he used was very coarse for these small pads

[@rfmerrill]

@@denisohbrien 100% agree. The flux that comes on the wick is never enough, even on the nicest wick available.

[@billd01rfc]

Nice - what is the WiFi module please? This may be flashable with another firmware for use outside of their app. I've done this with lots of Sonoff devices which use ESP8266 - would be interested in using this form-factor if I could.

[@bigclivedotcom]

Beken BK7231T0N32

[@TingFeng77]

Huh, mine has Bouffalo Lab BL602

[@tinygriffy]

jeah, why not use a wroom and a freaking relay in a junction box then .. probably comes in cheaper also and you know what you got

[@309electronics5]

Tuya ditched esp chips years ago so its impossible to find one (unless its another chinese brand who has great contact with tuya or has stock) all use beken chips or realtek. For which is openbeken

[@billd01rfc]

Because separate components in a box, with all the required relay, power circuits etc are bulky. I have amy of these already around the house. This form-factor is nice and neat if it can be hacked. Also, I like a challenge, and learning new things.@@tinygriffy

[@KeritechElectronics]

Nice little fix. Dead electrolytics, the true menace. Silicone glue on recombobulation, and it won't come apart before it is properly spudged. 6:32 ...and see if it was not a Fluke! :)

[@echothehusky]

There must have been thousands of these thrown away for this small fault. What a waste of resources!

[@bigclivedotcom]

I think this is just the tip of the iceberg of stuff that is ditched because of one cheap capacitor.

[@Techman83]

Freezing sockets like this is a good way of getting the glue to break free. Then they can be glued back together and be far less likely to come apart after (YMMV).

[@tin2001]

I'll have to try that next time I need to open a glued device. Sounds better than cutting and snapping stuff.

[@kimchristensen2175]

I probably would have powered it up with the PCB inserted onto the pins before soldering them, just to be sure there wasn't something else needing fixing. But yea, 95% of the time it's the output capacitors on these switching power supplies that go due to the high frequency ripple current punishment they endure.

[@gordonbaron9868]

Thank you so much for taking the time to look at this for me! there must be 1000s in the bin in UK! I will carry out your process for the other 8 i have and any further that go faulty, though the first batch still performing , once i get one running i will confirm the fix, those you have need a reset to default and app (smart life ) download , account and sync with your wifi , again Thank you for investigating and giving me the key to getting them working again , Happy new year !

[@williamterry3177]

Perhaps you can repair the with the solid type capacitors Clive mentioned.

[@AttilaAsztalos]

Q: Is connecting an electrolytic capacitor backwards the only way to get it go bang in a most exciting manner...? A: Oh, no. Dropping one of them into the molten solder bath of the selective soldering machine you're operating will do it quite nicely...

[@clownhands]

Clive, My favorite type of video! Why was the failed capacitor exposed to high frequency? Was it not smoothing rectified mains voltage?

[@MarshaJ8800TU]

The 4.7 400v cap filters the mains 50hz. The 470 10v cap is filtering 1Mhz from the KP3211 switching chip.

[@leybraith3561]

Here's another example of 'time-bomb' components- Just fixed a family's toy Christmas train, an expensive Disney themed setup. After a few Christmases' of use it couldn't run for long before crawling to a halt and 'motorboating.' (Strange describing a train engine as 'motorboating') 7.5V Battery (5 x C-cell powered) Examination revealed a very hot component in the power input stage of circuit board. It was a SMT Polyfuse. Intended, I assume, to reduce power if engine has stalled. Sadly polyfuses have a limited number of operations before triggering at lower and lower currents. This one was rated at 1.5A nom, 4A trip, 8v max The motor is PWM controlled, average currents seldom exceed 1 amp. Probably not a factor but PWM does produce high current peaks. Interestingly, the polyfuse partially recovered after it's ends were re-soldered. Not for long though. Replaced it with a slightly higher current rated through hole polyfuse (and a much higher max voltage rating). It happily passed a reasonable time-soak test. Happy Family.

[@johndododoe1411]

Not sure what behavior you refer to as "motorboating", it seems to be beyond my knowledge of tech slang and as non-tech slang it refers to a particular form of lovemaking . Also your dozens are more like scores (5 to 9 scores in mains frequency CPUs) .

[@ericmc6482]

Hi Clive. Pro Tip - slip a short length (12mm) of 1/4" silicone tubing over slightly shortened (2mm or so) solder sucker teflon tip for perfect seal and perfect solder removal. Works perfectly on single sided boards and THP boards when rosin flux is present. After a few hundred joints you may need to cut the silicone tubing back a couple of mm to expose new good end. If the teflon tip gets clogged (rarely) a quick poke with hot solder tip sorts it out. I have not bought any of that expensive solder wick stuff in 25 years haha. Thank you for such educational and informative content and the wry humour. Cheers from Downunder.

[@bigclivedotcom]

My Engineer-brand solder sucker has a silicone sleeve.

[@ericmc6482]

I thought of it first, 30 years ago lol.

[@SeanBZA]

@@ericmc6482 I used some rubber Hellerman sleeving I got off old wiring looms, and they worked well. Then used some PTFE sleeving I also got, which also works well.

[@TeddieBean]

Could we get an example of how to do this? I'm sick of using solder wick 😂

[@ericmc6482]

@@TeddieBean Just slip a length of silicone tubing over the teflon tip....search "Engineer-brand solder sucker" for an example.

[@leybraith3561]

@13'10" comment about 'That pesky capacitor' made me smile.... ...Bet the manufacturer smiles too, probably has a category for components that guarantee predictable medium term failure... maybe 'terminators'?

[@zyghom]

I bought over 30 smart sockets already, starting few years ago. Recently one by one all started failing. At the beginning the vendor replaced few broken sockets then he stopped. Finally I opened one by one and replaced capacitor - imagine: till today I replaced already all of them - wtf? They put so low quality capacitor or what? The ones I put where a bit higher voltage (16V), the originals were 10V - maybe this was the reason? The only big problem is: once the socket is opened, it will NEVER be the same again :-( Anyway, you nailed it ;-)

[@demef758]

Of all the switcher topologies, the buck is the gentlest on its filter capacitor. All other topographies are not so gentle. The buck has to accept a triangular current waveform with a DC component on top of it. The DC current is simply the load current. However, the triangular current goes directly to the filter capacitor, which ideally integrates the current as the capacitor then maintains a smooth DC voltage of the output. What kills this capacitor in the long run is the capacitor's Equivalent Series Resistance (ESR). The triangular current passes through the ESR. As everyone here knows, current passing through a resistor creates I^2*R power losses, which in turn creates heat. Capacitors do NOT like heat. Heat dries the capacitor, resulting in capacitor death. Vendors like China Inc.are seldom aware of these problems, so they use a cheap electrolytic capacitor, that has a very large ESR, as the switcher's output filter cap. Eventually, POOF! Clive did the proper thing here in reviving the switcher: he used a high quality Panasonic capacitor designed for switchers, meaning that capacitor has a low ESR. For the record, you can tell when a capacitor is rated for switching applications because its ESR is tested at 100 kHz, where a cheap low frequency capacitor is tested for 60 or 120 Hz.

[@Yrouel86]

I had to open a couple of my smart plugs to access the wifi module and its serial port (UART) to flash a custom firmware and those things are a pain to open, also I couldn't really desolder the PCB so I had to essentially pry it from the case just enough to solder some wires on the module contacts on the underside. As for closing them again I have to say a generous amount of hot glue around the border (applied before closing it) does a decent job at holding it together and also if you need to open it again for whatever reason you can let some isopropyl alcohol through the seam to unstick it

[@ctid107]

None of those pcb tracks look anything like capable of 16A at 240V !

[@rikardlalic7275]

Hi, Clive! As always, clear explanations and functioning product. What do you mean by a solid electrolytic capacitor, actually? A tantal one? Thanks.

[@bigclivedotcom]

There are interesting solid electrolyte capacitors for ultra high reliability.

[@someguy2741]

Flashback! Drunk Clive trying to read the voltage off the picture. Lol. It was classic. I dunno why I just remembered it.

[@bigclivedotcom]

It's happened since too. It would be so much easier than probing the real PCB.

[@HowardLeVert]

What I find sad is that I expect to have to replace capacitors in my old valve radios, some of which are now over 90 years old. I do NOT expect to have to replace them in objects that are a few years old.

[@tin2001]

Years? Some of these Chinese things last just a few weeks. That said, I hope the smart light switch I just put in the other day gives me a good 5-10 years service before it craps out. 😂

[@tompeddle]

I've had half a dozen of these (made by 'Teckin') for some time now, and I periodically have to replace the damn caps. A satisfyingly easy fix, but a pain. Naturally, I'm far too cheap to buy another one for a tenner! Made me laugh as soon as I saw the thumbnail, and thought 'oh god, not another one...'!

[@TeddieBean]

I have exactly the same ones and I'm so glad I can now easily fix the (four?) ones that have failed already in the same way!

[@niallreynolds9376]

About to embark on the same mission, would a better type cap negate to need to change em so often?

[@MattKing2023]

happy new year Clive and everyone watching

[@AliZainOnline]

470, 10v capacitor is the most common fault in smart plugs after a year or so especially with plugs remain ON all the time. One of the sign of this bad capacitor is the relay keep turung IN an OFF and smart plug unable to connect with WiFi.

[@TheGodpharma]

I was wincing at the possibility of burnt fingers while trying to de-solder that board.

[@Sanchaz12]

This video inspired me to actually try fixing my half-broken Blitzwolf smart plug I had laying around. It started acting up while turned on, causing the relay to click off and on for a split second every few minutes. Thankfully it was easy to open as it was just screwed together and no glue/plastic had to be cut. Inside I found two 4.7uF 400V and one 220uF 10V capacitor. I remembered I had a capacitor kit I bought a while back, and it included a 220uF 10V capacitor. I got the old one out, and put the new one in. To my surprise, that was all it took to make it work normally again! To be honest I didn't expect the issue to be as obvious as a capacitor since it's only a few years old by now, but when you talked about failure by high frequency I though it was worth a shot to fix it. As the capacitor kit came from AliExpress with just generic no-name capacitors I expect the plug to fail again some time later, but at least now I know what to replace!

[@davidfalconer8913]

You might invest in a tubular hand held vacuum solder sucker to clear those holes , but a STAINLESS steel needle is also effective , as it will NOT accept solder ( unless you dip it in A8 acid flux ! ! ) Ha - Ha ...... DAVE™ 🛑

[@DUKE_of_RAMBLE]

A.... "Fun" button on an electrical testing device is _never_ ominous... 😏🤣 What's that button do, anyways? Just a menu/modes button with an Engrish labeling?

[@CraftyOldGit]

I had four unbranded smart plugs from Amazon that looked exactly like the ones you work on here. They all failed at the same time so I assumed a software problem. Found several articles on how to reset them but nothing worked. In the end I gave up & sold them on eBay as 'not working -- spares or repair'. I wonder if the buyer got them working.

[@ericfrazer4736]

XiangHeWang (pronounced schwing-he-wang) - guessing that's the global docking merger of PingWeeDong and WanLongDong.

[@leybraith3561]

​ @MarshaJ8800TU suggests the failed cap is coping with 1MHz from the KP3211 switching chip ... amazing frequency for a power supply. Cant find an exact spec sheet but I see other examples running up to 1.2MHz (e.g. A7525 from AiT) Quite a revolution, I'm used to thinking 60KHz is a high-ish switch-mode SMPS freq if you want reliability. Can't believe an electrolytic doesn't instantly let out the smoke when absorbing power at those frequencies. Bet they run hot and dry out quickly.... hey...wait.... that means even quality products won't last very long....mmmmm,...

[@leybraith3561]

Data sheet says LP3211 runs at 0.9 to 1.5 MHZ

[@abitofabitofabit4404]

Usually they use ceramic caps for power supplies at those frequencies, which likewise have become amazing performers in recent decades. An extra 100nF in parallel might have doubled the life of the electrolytic or more.

[@robertburrows6612]

I use a lot of those WiFi sockets. (Yes I do a lot of home automation , because I a lazy git ) I wouldn't use a load above 10amps with them, mine are used for light loads such as table lamps ect. . Theses WiFi sockets are usually very reliable, I only had one failure in 10 years I've got 15 in use around my house , to be honest there cheap so repair is not worth while, but a very interesting video nevertheless

You can clear out through-holes with a wooden toothpick. Always fascinated that you don't need a helping hand for this kind of jobs, i would burn myself for sure. ;)

[@petergamache5368]

Undersized or "optimistically rated" relays are the hallmark of cheap smart plugs, as are anemic high-current traces. When I need five, I buy ten!

[@puppet-head]

I do wonder if a market will start up for fixing EV chargers, rather more expensive to replace than dinky plugs, but doing much the same thing.

[@fluffyblue4006]

I also tried to repair a similar item. Except, mine had that special aroma... Opened it up, lifted out the prints, was greeted by a huge black skidmark on the inside and some more of that aroma. The supply board itself had a hole that looked like the caldera of an inactive volcano. I couldn't make out what caused the problem. Probably one of those components that were now degraded into black crumbles, loose in the bottom of the enclosure. I tried giving it 5V from a bench PSU but there was no life anymore.

[@just_saw_dust]

Thankfully UK sockets are generally switched so if the cover of such devices comes away then we can isolate it. Sideways glance to Technology Connections 👀

[@JessicaFEREM]

this comes off to me as a "SmartLife" compatible smart switch. these are the most common cheap ones over in the US. the round shape and chinese origin give it away for me.

[@carlyonbay45]

I wouldn’t have these things in the house 😳

[@muzikman2008]

It doesn't help that there is no ventilation in these devices, a bit like phone chargers, wall warts etc.. Heat kills capacitors eventually 🧐

[@dj1NM3]

Perhaps a "solder sucker" might be a useful purchase for desoldering? There are fancy ones with an iron built into them, so you don't need three hands.

[@johndododoe1411]

Big Clive has more experience than most of us combined and the skill to hold 2 things with one hand . He probably doesn't need expensive motorized tools like the one you suggest .

[@bigclivedotcom]

I have a wide selection of them, but don't always use them.

[@OscarSommerbo]

Those are mainly useful for (almost) desoldering ICs, and even then you have to go in with the braid to clean up. Just switching a single two legged component, it is rarely worth it unless the desoldering station is permanently set up.

[@jamesplotkin4674]

I fear a higher temperature iron would hasten the demise of the circuit traces. I prefer a "solder sucker" which works well.

[@WereCatf]

This is quite a timely video; I've got a very nice WiFi-enabled schuko-type relay that can also measure voltage, amperage, power factor and all that and I've been using it happily for over a year, but it's just recently started to randomly crash. I assumed one or more of the caps inside've gone bad, so I'll need to open it up one of these days and see about it. Probably going to be about as easy a fix as in your video.

[@devttyUSB0]

Nice and easy fix!! I miss the diag bit though. 😊 Did you really spot that cap and went for it? 😉

[@bigclivedotcom]

Its one of the most common failures. The dim LED was probably a low or unstable supply voltage causing the processor to fail to boot.

[@Loscha]

ELECTRIC HAZARD!

[@willthecat3861]

Current through a capacitor is roughly proportional to the sum of the currents produced by the first few harmonics... anyway the higher the frequency the more the current... and that produces heat...due to the capacitor's ESR. The heat drys out, or 'boils' off the volatile components of the electrolyte. Electrolytic capacitors have a relatively high ESR compared to other types... and cheap electrolytics have a higher ESR than more expensive ones. Capacitors rated for higher temperatures can handle higher currents without failing as quickly.

[@davidtaylor7681]

Anything labelled 'smart' is probably better off broken.

[@Incognitus-Umbra]

Thanks Clive

[@nomusicrc]

I'm jealous of your Chinese soldering iron how the tips stays tinned. I have an expensive adjustable one and seconds after I've tinned the tip it corrodes I have it set at 355°C I'm not sure if that's too low or high

[@bigclivedotcom]

I wonder how accurate your temperature reading is.

[@nomusicrc]

@@bigclivedotcom What temperature should it be at

[@tinygriffy]

maybe also check your solder .. should have acid free flux ;)

[@tinygriffy]

@@nomusicrc355 is not over the top ... a good tip should be able to handle 420°C for a prolonged time .. ie hundreds of hours

[@nomusicrc]

@@tinygriffy but I'm wondering why his Chinese soldering iron stays tinned but my expensive one doesn't I don't know if I'm cooking the solder that's on the tip or if it's too low

[@ConstantlyDamaged]

Perhaps test the plastic with some two-part epoxy? I am sure a little of that around that edge would ensure a good seal again.

[@bigclivedotcom]

Resin is not reliable with soft plastics.

[@ericmc6482]

Hi Clive. Second Pro Tip - folding the end of solder wick back 5mm or so forms a nice pad that sucks up all remnant solder and protects pads from damage. Cheers.

[@ThunderBassistJay]

For a moment my brain tricked me smelling the solder. 😀 All the best for 2024, Clive!

[@mickfountain6328]

Thanks Big Clive. A 3D printed band (vase mode) glued to edge of base and to cover increases glued surface area for safety

[@fazergazer]

Wrong capacitor for the job, glad to see it’s fixable!❤

[@JoFreddieRevDr]

Big Clive the Electrician, can we fix it, yes we can...

[@davelowets]

The little side button on such devices are usually there to allow you to turn the socket on if you are near it and don't have a phone handy to switch it in the app, AND also there to hold it and reset the device and clear out any account info.

[@ColinWatters]

If God had intended us to solder things he would have given us at least three hands.

[@whitesapphire5865]

This is useful to know.... I bought a set of four from Wilko when they were selling up. I have yet to introduce the juice to them, but my intention is to use them for turning on the Christmas lights next year. They look identical to the one you have there ....

[@thebatu89]

Someone posted that you can remove the casing by using clamps or heat the edges with hot air just enough to loosen the adhesive with no damage

[@samuelfellows6923]

😐 - I have much “older” style radio remote controlled sockets that appear to have lost their range, are meant to have a range of 16 feet (between socket-remote) but now a range of 3 feet ~ even with new 12v batteries and sticking my other arm to act as an antenna 😠. Don’t know if something has failed in the sockets, or they consist of “Chineseum crap” and I need to replace them with WI-FI/smartphone controlled ones

[@bigclivedotcom]

Could be ambient electrical noise, or it could be more ripple on the receiver's power supply due to degradation of a dropper capacitor.

[@piconano]

I clutched my pearls like a Karen, when you desoldered the holes. What kills these caps, is the ripple current. To lessen this effect, they should use two or more caps in parallel to get lower ESR and share the ripple current between the caps.

[@fredflintstone1]

nice to see a repair video rather than a strip down one way video 🙂

[@bigclivedotcom]

Almost everything I strip apart gets reassembled afterwards.

[@MC-emmcee]

I hate it when they weld cases together. Why can these casings not use screws so that they can be easily repairable by the competent/knowledgable person. After all, they sell normal plugs that facilitate "ordinary" (sometimes incompetent) people to attach their own plug to appliances. Some people are going to try and repair items like this anyway so surely it would be sensible for them to have screw-together casings because, as Clive pointed out, botching the case back together only makes it more dangererous. Also, repairability is a lot better for the environment.

[@tinygriffy]

because they make money only by selling lots of these and have them fail as soon as possible .. it is a crime imho

[@tinygriffy]

Couple million solder joints on record .. masterfully single-handedly doing the most difficult connections .. still wondering if it might go horribly wrong .. 😆

[@tonyweavers4292]

I had a couple of these fail. I ended up binning them as the case was buggered getting it apart. I wish I kept them now.

[@M0LHA]

To be honest you can buy them for next to nothing now. I believe they are between £5-10. I kind of want to put one outside and shove an electric heater on one to see what would happen :)

[@u.e.u.e.]

Happy New Year! 🥂🍾 Thank you for avoiding electronic waste once again. 😃👍

[@mikenco]

Is that new knock-off HOPI? I feel I must have missed the vid that introduced that.

[@bigclivedotcom]

It has a different range, but a dimmer display. Both get used.

[@TheBlibo]

And the cure for this is don't buy Chinese

[@mrslade]

'Bangy, fizzy, poppy" Lol😂😅

[@Kineth1]

I'm so glad your AnTai meter has a fun button. Is it really fun?

[@bigclivedotcom]

It launches nuclear missiles.

[@SinKillerJ]

On the plus, liquid metal sploshes are always so satisfying.

[@generaldisarray]

To clean out really troublesome througholes I'll push a wooden toothpick through the hole while I melt the solder with my iron. 99.999% of the time it's always a capacitor that's gone pop... Excellent repair Clive. Merry Christmas and a very Happ New Year... 🎄🎄🎄☃☃☃🎅🏿🎅🏿🎅🏿

[@GadgetReviewVideos]

Yup, I bought a few brands of wifi smart lights. Two from the one brand I was testing failed. They all advertise 25000 hours with LEDs but that’s depends on the quality of the other components. For the VoColink brand they both failed with swollen capacitors.

[@Slikx666]

Another reason to use a standard switch, no extra angry pixie wrangling to go wrong.

[@tinygriffy]

jeah right.. what became of moving ones ass 🙈

[@hippopotamus86]

I have the same plugs, but branded as Athom plugs. I bricked one flashing the TASMOTA firmware. The internals are the same as this but with ESP

[@Alacritous]

That's what I look for first. Scorch marks and domed caps. I've rebuilt the power supplies in several of my ACER monitors because they're crap design and keep blowing their caps. But they are consistent.

[@martinandroid2538]

You r dexterity amazes me. :)

[@Goodchappy]

I bought 16 of these from Amazon about 2 years ago, branded as "Teckin". They work really well until they start turning on and off randomly and then refuse to come on at all. I tried to get one apart but realised that the case would be unsafe even if I repaired them. Only 10 of the original 16 still work.

[@SakosTechSpot]

I recently was working with an older computer and there were 6 capacitors that were domed like crazy. The computer would boot and you can access the bios, but when you actually tried to load into any OS, it would reboot immediately after the loading screen. I wanted to fix it, but I don't have capacitors on hand and it wasn't worth ordering them to fix a 15+ year old computer that I just wanted to tinker with.

[@leybraith3561]

I've done numerous repairs of low end gear involving similar caps glued to (or very close to) overworked heatsinks or coils... Pretty much guarantees the item survives the enthusiastic ''new-toy' period and fails when the user might be in the mood for another new toy.

[@lostjohnny9000]

Great Bukkake solder show.