Autopsy on exploded remote control socket.
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- čas přidán 21. 07. 2018
- This pre-exploded device was sent in by Timothy, who had been using it, then after storing it for a while plugged it back in and it promptly exploded and took the breaker out on the circuit.
The fault is down to a bit of a design weakness in a unit that seems quite well designed otherwise.
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.com/coffee.htm
This also keeps the channel independent of CZcams's advertising algorithms allowing it to be a bit more dangerous and naughty. - Věda a technologie
You have an uncanny knack of explaining things so that even a total electronics newbie like me can understand it.
He'd make a brilliant teacher.
Very enlightening. About 10-15 years ago I filled the house with remote/home automation stuff from a range called HomeEasy, that used to be stocked by B&Q among others. Most of the lighting switches were TRIAC-based dimmers, and so were incompatible with CFL and early LED bulbs that were phased in shortly after. I retried those in favour of old-school mechanical wall switches, but I kept the socket switches for use with desk lamps, aquarium lighting, computer monitors etc. Over time a good 50% of these have failed in the way described here (the relay failure, not the explosion!) but I kept them because I had a gut feeling it was a relatively simple fix. I thought it might be the actual relays, but I shall have a couple of them apart over Christmas to check their capacitors.
AvE brought me here. 👍
The angry pixies bought me too
The mildly annoyed pixies brought me
Colin Scholz :D the electrical firestarter vijeo
I found AvE through Clive.
One comes with the other! AvE and BigClive are the CZcams poster Guys!!👍👍👍
I don't recall ever coming across a resistor failing short circuit. I have heard stories told around engineering department campfires, about a guy who knew a guy, who's cousin had a resistor go short circuit once, but most people think it is just an urban legend.
I love these autopsies. The more catastrophic, the better and this is a beautiful example of such an event. My sympathies about your dead knob, Clive, I can imagine it was very difficult at that juncture.
That resistor would carry ¼W under normal use at 233V, more at 240V. Yet it looks like ⅛W in size. Even at nominal 240V² / 220K it exceeds ¼W, and at peak 253V² / 209K it would receive 306mW . If it had been for a 230V±10% plug standard nominal would have been 240mW but tolerance margin still 306mW (all assuming 5% resistor).
John Francis Doe - Yep. If it is actually 220k ohms and the voltage across it is actually 240V AC, the power dissipated would be 262mW. Note however that the rest of the circuitry runs from a lower voltage supply. If the relay is a 24V type and a 24V Zener diode is used to provide this supply, the voltage across the 220k ohm resistor will be the supply voltage minus the 24V Zener voltage. Also if a resistor is not in free air (in this case covered by the capacitor) it should be derated anyway. So the resistor the manufacturer fitted was operating well outside it's rating. IMHO, the 220k resistor should be 470k ohms or 1M ohms, a metal film 250mW type or better should have been used, and it should not have been positioned under another component. Finally, a series fuseable resistor should have been included in series between the line/live connection and the junction of the X2 capacitor/discharge resistor.
It's worse. The rating for the resistor is free air. That location severly compromises the rating. I am not sure that cap needs a pre-heater either.
Agreed. That resistor placement is pretty bad design. The X2 rating of the capacitor is compromised by it, as well.
I think it may be the "glue of death" - that light to dark brown glue that used in consumer electronics like this. EEVBlog had a video about that glue become conductive in his speakers. In blown unit there definitely was that glue under the yellow capacitor, so probably it got onto that resistor and once it becase conductive enough it just arced across the resistor (which was probably also corroded because of that glue).
That's what I kept wondering, as to why it exploded, Ye old Chinese dookie glue. Sounds about right to me. Makc K.
Yes, I think Max K. is right! I've seen this brown conductive glue in amplifiers. It starts out white and over time and heat it becomes more brown and conductive.
PuchMaxi i hope my Technics 5.1 Unit doesnt have this crap Inside...
That's very possible. I had a computer power supply that just straight up exploded due to the glue becoming conductive.
I wonder if they use that glue intentionally, so that it would fail after a few years.
I love how the explosion metal coated the plastic. Real-life vapor deposition.
That is exactly what I was thinking! I wonder if the process can be harvested.
They really should have built a pie dish into that switch.
Improved my Sunday no end to hear Clive's dulcet tones uttering the magic words *"What's the worst that could happen?"* Anticipatory thoughts of explosions to come in a video not far from you..(tube)
The worst that could happen?? Echoes, Stir of Echoes, watch it, a good movie. bren 106
Talk about leaving an epic skid mark, speaks wonders of using the correct enclosure for mains devices lol
I like that Wera driver set.
z0rkmids do you know the exact name of it?
Holder Hilder it was the 2017 advent calendar set. It’s very nice. Not available any more though. Maybe on eBay though. Hope this helps
John Laney hey thanks this helps a lot. I’m going to look for it on eBay. Thanks for the info
After a while in the tool bag that lovely velcro case becomes a used dish rag, the number one drivers for me but in a poop case
Although the advert is not available anymore, you can buy the toolset: www.amazon.de/WERA-Kraftform-Mini-Schraubwerkstatt-34-teilig/dp/B079RB6MJF
Look forward to these vids daily. Never thought something so entertaining could be so clear and educational. Thanks for the time Clive! 😁
Ashens reviewed that Wera calender in the 2017 specials.
Not only is this interesting and informative - your video production quality is excellent.
Hi Clive. Just want to tell you the more I watch your videos the more I love them. You are one of my top 5 favorite you tubers out there. Thanks for all you do.
A good few models of Yamaha AV-receivers / home theater (5.1-7.1) amplifiers / soundbars use a capacitive dropper in series with a small 50Hz transformer, as part of the stand-by power supply, and that dropper capacitor often fails in this exact manner (loses capacity => no more power-on). I revived a sound-bar a couple years back, by replacing just that part.
On the next video: Taking apart and fixing the meter!
Kei _ it might upset Joe Smith if Clive starts doing meter repairs... I suggest a colab...
Combustion Kills Joe got upset the minute Clive showed the broken meter on camera lol
Anyway, i think it would be nothing wrong to take it apart, do autopsy and show how well components are chosen. And maybe to show how this is actually are easy to fix it.
A fascinating journey with BigClive and well explain as always. Your a joy to listen too and your knowledge and abilities always lift me up to a better understanding. Superb teacher. Thank you Clive👍
bigclive is definately the CSI of electronics when it comes to reconstruction of the failure point!
Im betting you can fix your meter. That being said have ya ever heard the saying, an electrician's house always needs electrical work, a plumbers house always has a leak, and a carpenter's house always needs carpentry work etc, etc.
Raymond Mucklow I don't know. The detents on those are usually just plastic cantilevers, and maybe you could epoxy it but I think before long it'd just crack again at the interface...you might do something with a long strip of spring steel bent into the right shape, but I don't know how you'd affix it so it'd be sturdy enough.
lexie 3d print a new part... done, finished, over with... unless it breaks again...
Raymond Mucklow Shoemaker's kids always have holes in their shoes.
Having lived in what was formerly an electricians house, can confirm.
Raymond, maybe bc. Electrician can fix em, others just ignore it as long as it won't kill em. :) (IMHO)
"The Amecal meter... has just done the Amecal thing". Clive, you've made my day.
Let's also add, it's Made in China. xD
I thought I recognised that screwdriver set from somewhere... It's the Ashens & Nerdcubed advent calendar of the year (2017)!
I've learnt so much about basic electronics watching these autopsy videos the last couple years.
If you ever start a merch line I strongly suggest a shirt that says "This is quite interesting..."
Thanks bigclivedotcom. I have 2 of these which have been switching themselves at random times. I checked the 220nf capacitor and sure enough, was reading low Have now ordered a couple of replacements and took you advice on changing the resistors to 470k.
Thanks again as I was about to dump them .
Picking a resistor like this and placing it where it was, is big design fail and doesn't instill confidence. The resistor is underrated, both in power and voltage, and placing it under the capacitor also means its operating conditions have to be derated even further.
I had the voltage dropper cap fail on an outside montion sensor lamp. I first thought water or at least dew had somehoe leaked into the sensor, because the lamp was switching on and off all the time, but stopped doing that every day an hour after sunset. At some point it didn't stop at all (but it was still staying off during daylight). I replaced the cap and it worked fine again. I cut the cap open and the metallized layer had degraded. It looked like it had been eaten away by something and also had small weblike breaks in the layer.
Good a fellow Scot explaining these bloody things they certainly have a limited life. I have gone through many over the years.
It looks like one of those ones that LGR made a video on recently that you could control from your computer. early implementation of home automation
For years I thought I was imagining electric shocks from unplugged power supplies, usually shocked when rolling up the lead, thanks for clearing this up for me
You, Clive, are a genius. See that? Period
Ave told me about you, awesome channel brother!!! Can wait to view them all.....
Well, you know what the Borg says; "Resistance is Futile!"... :P
Ohm my goes..
Anxious to see a video on your meter repair! 👍 😁 👌
AvE sent me. And I am glad.
Thank you Jake! His tools always drive me nuts haha. I wonder if he realizes how much that calendar was worth.
I had that meter problem with the ST-9927T. It was easily fixed, and improved, with some epoxy.
Excellent and I can't wait to see the meter fix.
I got the same advent calendar a couple of years ago, nice set. :-)
I've seen similar stunts pulled with neon indicators, little 1/10w resistors in series and crammed inside the neon indicators housing.
Thanks Sir for this video, Cripes!, I've got 6 of those, only 2 still work properly. I didn't realise they could explode. Don't know whether to repair the ones that dont respond or switch off at random. I'd like to hope newer designs are better.
And great video on the circuitry
High quality screw drivers by Wera, I love these tools, I use nothing else anymore.
im jealous that's a really nice screw driver set
I have a little screwdriver kit from Wiha that I bought off ebay. Very nice, compact, many, many bits and a lovely sliding metal case. Though I do like your little kit because it doesn't let the bits fall off until you twist them. (Sounds like life, eh?)
I sure hope the manufacturer of this product finds this video and sends you some money in gratitude. You just showed them how to improve the quality and longevity of their product. That is definitely worth something. Really enjoyed the video as always. :D
Surely the manufacturer knew or learned the weaknesses of their own product long before now. Warranty returns alone will teach you that.
i didn't expect it to have thermal fuse. but very good. i plan to modify or build some of my stuff with 1-2 thermal cutoffs in strategic place. i mean if you add mov it's a must anyway. sounds very cheap fire protection measure. might actually test some from bag, who knows if they made them correctly...
Ashens and Nerdcubed have a series of them opening the Wera advent calendar and gradually becoming depressingly aware of how boring they are, or how bad the ones designed for kids are.
Can be found on the extraashens channel. Worth a look just to see how insane two men can become.
Oh god the spice.
That WERA (not i but e like in the word era) looks really cool. I hate all the tip change tools but that looks really good. I have many Wera screwdrivers and I know that the quality is really high.
AvE brought me here. You showed me some interesting stuff. Now I’m here to stay.
It looks like that creamy looking glue that has turned brown may well have started the failure as it go's acid over time and starts conducting & corroding parts, I have repaired or written off many items due to this garbage glue that is still used today (first came across it in the 80's) . I was hoping you were going to do an ohms test on the brown bits of glue .
The omission of the 7mm socket is bordering on criminal.
Clive didn't mention any lack of 7mm socket.
What 7mm socket do you mean?
Great content, directed here by AvE 👍👍👍
The screwdriver set from Wera is really expensive, we have them here in Spain from a German company called Bauhaus, like B&Q not sure if its their brand, they sell various packs of high quality kits, screwdriver range kits from 40 euros upwards , individual drivers from 5 upwards. lucky and very nice gift, I have a normal set and a high voltage set with the keys for all the electric cabinet locks etc and fuse removers etc, very high quality, I use mine daily and have not damaged them in 10 years of continual use green and black is non electric, red and yellow electric (no metal in the handle)
Hi, I see the trick of resistor hidend under the capacitor in a chinese alim. I don't understand why a capacitor have 4 legs .... after time, I see the resistor under.
Sorry for my poor language, I'm french !
J'ai déjà vu le piège de la résistance cachée sous un condensateur dans une alim chinoise à bas coût. Je me demandais pourquoi un condensateur X2 avait 4 pattes.:-))
Your videos are the better for explanations and I love the picture of circuits you make . Bye from France
I've seen X2 safety capacitors that have that discharge resistor inside the plastic casing (at least according to the datasheet).
The switch on my Amecal 9927 failed too, the plastic moulding on the back of the function knob that drives the switch round failed. I carefully reassembled the broken fragments of plastic with epoxy then surrounded the moulding with a small piece of Perspex sheet with a hole drilled to size and again held in place with epoxy. So far so good !
The original manufacturer of that failed amecal is Extech
I think Extech is just another branding of the same style of meter from the same factory.
The original manufacturer is CEM Everbest Instruments. They don't usually sell anything under their own brand.
That screwdriver set is nice
Wow...talk about a trip down memory lane. My folks used to have the North American version of these wireless controllers about 28 years ago. If memory serves right, I believe one of them shorted as well but not to the extent as the one you examined. Blast from the past!
At first glance and using the SWAG method ... I would hazard that it got "tagged" by lightning ... a near hit to the line that causes a high induced spike or a direct hit somewhere back down the AC distribution supply lines . At least that is what it reminds me of .
As a wiser man than myself said to me when I was young and just starting out ... "with a lightning tag , all the bets are off" .
Clive, i have noticed you haven't used your catchphrase lately and I'm missing it..."One moment please"
Oh, i didn't watch long enough...YAY you said it!!!
You opened up all the advent calendar at once? You'll go straight to hell for that! ;)
One would have to be a believer for that to be a deterrent.
You don't believe in the magic of advent calendars? You'll go straight to hell for that too! ;)
Are you sure you are not taking a joke just a little too seriously?
Incidentally now we've got past the taking the joke too seriously, if you are interested in engines, I have many on my channel featuring both internal and external combustion. (In one case the external combustion is roughly 93 million miles away.)
@Old Farfegnugen hahha!!!!and no one noticed, numpties, quality comment Sir!
A little late to the party, but a recent discoverer and fan of your channel. Great work, and could listen to you till the coos came hame!
So, as it happens I'm also a Scot, of similar age, and a veteran of Maplin catalogues with a Concorde on the cover!
I noticed with this little horror, the labelling on the back actually has the classic 'Chinese CE mark', wrongly spaced yet subtly similar! Acquaintance of mine reckons it stands for 'Chinese Excrement'. Its a nasty dodge they pull when in fact the product has been nowhere near a CE certified testing lab, but since the mark isn't correct CE they don't tech infringe, they simply IP infringe!! (CE marking design is specified in detail in terms of the size, shape, geometry, etc. And ultimately marking is also self-certified!)
On the flip side- another quick tale- I designed a product needing tested for CE compliance, had it tested by Inter**k in the UK, passed with flying colours. Manufacturing partner in China, with UK management, raised concerns about a TRIAC rating and we had it retested by TuV, Shenzen...marginally failed! Exact same test parameters to CE under EN/BS standard...so, doubled the amp rating and then all good.
Moral, however: not everything in China is dodgy, and not everything in UK, it seems, is better... :)
I like to think of the Chinese CE as meaning Caveat Emptor. (Buyer beware.)
That could be the new European standard! ☠️
I always say that UK plugs are the best engineered piece of technology because they usually each individually have their own copper fuses inside the plug so that if one plug blows, it doesn't trip the entire circuit to the house. Infact it's very rare for houses in the UK to have their circuits trip with a failed fuse, however that said you can still trip the main circuit if things get too overloaded. It's happened with an all electrical cooker before, turned on the grill for the cooker oven and it caused the mains to cut off because it tripped,.which is rather weird because it wasn't like we were overloading the circuit, but it would keep tripping each time we tried to use the grill on the oven. Eventually it did work OK again without tripping after flipping the switch on the fuse box. It's just too weird for something like that to happen. So I wonder if it was a fault in the circuitry for that cooker that kept tripping.
I think I'll have to take mine a part and check the capacitor !
I am going to get that driver set. If Clive says "very good", I buy.
BLACK SOOT = COOL
I worked for a fire investigator and learned that the black soot shows the parts that were cool during the fire.
The clean parts were the hottest.
Kind of surprised that iFixit hasn't offered you a sponsorship by now :)
Jason Hardman why should they, they tear their own stuff apart and Clive easily has almost every bit that's needed to screw something open. :P
They need it because nobody says "spudger" in such an inviting manner as Clive.
Perhaps a video explaining discharge resistors and their voltage ratings and power dissipation would be a worthwhile follow up video.
Hey Clive, just a thought, the Wera ratchet screwdriver I gave you at last year's Glasgow meet up should probably fit into that pouch, in case you wanted to swap it out (it would work quite well with the sockets as well as the driver bits).
How cool is that, I've got one of these was turning of by itself. Thought always it was the neighbour with his remote :D
now I can fix it, thanks !
Oh, it finally got released :D
EpicLPer I swear, I see you on every video :3
That advent calendar killed it on Ashens' and Nerd Cubed's Christmas competition.
Quite the stylish wad of soulder there, Clive. So, where's the NEW smoke and fire? OK, good fix.
I know this is an older video. But that switch on the meter being bad reminds me of the issue I had with the brake pedal position sensor on my truck. Of course all newer vehicles have to be smart™️. Which generally means "more stuff to break."
So the vehicle starts throwing a code that activates the check engine light. Use my handy Bluetooth code reader.. Comes back with a code that's listed as "UNDEFINED".. Apparently they implemented that particular trouble code, made it serious enough to trip the engine light, which disables remote start and other things that make freezing cold winter more fun.. But haven't gotten around in over a decade to actually define said code.
After days of troubleshooting and process of elimination, I narrow it down to brake pedal position sensor. 2 sprays from a can of contact cleaner without even disassembling anything.. Problem solved. Two years later.. Not a single recurrence of said issue.
Good times. Who could have imagined that a completely not sealed, not shielded rotary wiper contacty switch/sensor down near the floor of a work vehicle, constantly exposed to dirt, dust, mud, moisture, etc. Could ever possibly be a problem.
Thanks for sharing:-)
Nice rebuild :-)
Wera is not only quite prominent but also an expensive, high quality brand. Wera tools are usually used in industrial environment. In Germany at least.
That system of wireless household controls reminds me of the BSR "X-10" System. RadioShack/Tandy sold them under their trademark "Plug 'n Power". I wonder if their radio codes and frequencies were compatible?
At Christmas I will send you an advent calendar that I saw last year.
It was by Haynes, the Owner's Workshop Manual folks and each window contained an electronic component. Once you'd opened them all, you had all you needed to build an FM radio.
Very good kit Wera they have four different designs of that model
Clive my Teco 7200 (single phase in three phase out) went out. I have it apart and I can’t see any blackened components on any of the boards. But there is one part that has two huge capacitors that I’m afraid to take apart. They’re about 45 millimeters wide and 90mm long each.
You could inline an actual (4 amp or matching the combined load of this thevice and whatever device it will control) fuse in one of the wires going to the plug, use one of those through hole PCB mounted fuses or fuse holders, some heatshrink sleeved on top. Or get fancy and mod it to have an accessible fuse.
Definitely run any of these using an extension cord with a proper fused plug.
Oh no! Not déjà ju again!?!? Thanks Clive, well reasoned ... perhaps we should we call you “electronic’s Quincy” in future :-)
I was looking at some of these (for U.S. current). What I really wanted was one that I could wire into my wall switch so it wouldn't need a battery for the remote and so I could use one switch to control it and the one outlet that is already connected to the switch. What I discovered? If there was such a product there didn't seem to be a way to search through all the other options to find what I was looking for, and the things that were the closest to what I wanted were for some reason 5x as expensive as the ones that used batteries.
Not the sort of device I'd use... never been too trusting of those contraptions.
Don't need automatic lights... just leave the hall light on and in the unlikely event of an intruder there's a 4 legged friend awaiting their arrival with bare teeth, raised hackles and aggressive growl.
Interesting, one of the leccy board energy saving guys came around years ago and gave me a load of energy saving bulbs and a set of those exact remote sockets so I guess the ones you have are likely similar provenance. Mine are barely used but I'll be doing some preventative maintenance if I do.
'Wera' is a very, *very* nice brand of handicraft tools.They seem to be more focussed on general DIY or maybe clock-making than 'Engineer' who primarily cater for the electronics hobbyist, but are of equal standing in my opinion. Sadly they are also *extortionately* expensive. For a decent selection of bits you need to spend abut £60-£90. The quality is _better_ than good, but the cost is insane and I would not recommend them to anyone because of it. Definitely _not_ even remotely pocket-money prices. Not unless you buy each bit one by one and then save up a month for the handle!
same happened with my 830 multimeter (same style as your amecal, with additional on/off button). the plastic that connected the knob with the contact group has broken.
I have three on order. I hope they last for a while,but if they do fail,I now have a good idea where to look.
Congratulations Clive on your Wera screwdriver set. Hopefully you wont go back to lead tipped screwdrivers again :)
A point that may assist people in the U.K.: if you own plug-in items like the device in the video and are not sure if the manufacturer included any proper protection, you can either use an extension lead and fit a 3A fuse in the plug of the extension lead, or use a 2 or 3 way adapter that includes a fuse, and fit a 3A fuse in said adapter. Similarly, for items that have a "Euro" style plug, use a good quality fused adapter and fit a 3A fuse in it. Personally I would prefer the EU to make including proper production mandatory in any mains powered devices / appliances. For plug-in electronics, a PCB mounting fuse (less than 40 pence) or a fusible resistor (less than 15 pence) would not greatly increase the cost.
OMG, my new message tone, 6:56 "there's a big skid mark over here, not where I was expecting it"
Don't think of it with your eyes shut...
Wera do make some very nice tools I have to say ,.. I used their hex keys (metric and imperial) daily and i much prefer them to the teng and snap on ones I used to use
Those look like UK X10 modules. Still have a large collection of the US versions, but never had one blow up. In fact, I fixed a couple of unresponsive 70's-era modules by replacing the leaky 'lytics. :D
Was there any of that brownish glue around the resistor leads?
That stuff is well known to get conductive over time (and heat) when it turns black.
I would love to get one of those toolkits as featured by Ashens.
Next video...autopsy on AMECal.
I was thinking same. Lets see what failed then :-)
I'd be pissed if that amecal was mine, considering it's almost 50eur for a basic multimeter with no special functions that i could see
@8 min,8 sec-"C'mon, get out" reminded me of the Glasgow tram conductress from my youth ("clippie") whose catch phrase was "C'mon, ge'aff"
not surprised that resistor failed, it looks an eighth watt, they're only about 125v rated, plus a 220k will be dissipating about a quarter watt, so overloaded twice! i've just replaced a 220k neon feed resistor as its gone open circuit, it was a quarter watt, and its dissipation less than a quarter watt, but it still looked 'cooked' ... i dont like running these tiddly resistors at these sort of voltages, high value resistors going high or open was a big problem in a lot of 'lesser brand' crt tvs in the 90's, causing runaway psu destruction..
The Wera advent calender, so much yes!
Wouldn't 240V across a 220K resistor be constantly dissipating about 0.25W of power? Not surprising the resistor failed if it's not rated for that.
d2factotum - if it has 240V across it, 262mW.