That brand of cap failed in a cheap flame lamp that had run less than 20 hours. Thank you for making electronics, engineering, and circuitry into a wonderfully digestible affair.

I really like it when you go off track for a bit. The hint about monitor picture tearing at the corner was really useful... as was the quick way of measuring ripple with a meter set to AC. These are the tit-bits that you usually only pick-up with experience. Great video and interesting as always.

This video just proved why Bigclive is my favourite electronics youtuber. I learnt a lot in this short 15 mins. Thank you.

That sort of 'blip blip blip blip' of the LEDs was a dead giveaway the power supply was faulty. It's a common failure mode on switch mode supplies. I go straight to the caps if I see that, and it solves the issue almost every time. I've seen it on everything from TVs to wall warts. Nice explanation of ESR.

Big Clive, the master troubleshooter Got a dead smart plug for a router He cobbled that wreck With caps, out of spec Now The Net's back on Matt's computer

The 2000 hrs is when run at their max rated temperature. Usually 85degC.

I really appreciate everything that was included in this video; a very down to earth description of AC ripple, great explanation of the power supply and contextual relevant tangents. It what makes this channel so relevant and valuable.

The capacitor that failed is next to the diode. Those are almost always the first thing that fails in flyback topology power supplies since they are directly exposed to the raw ripple current. When I repair PSUs, I add a 10uF MLCC across the electrolytic's leads on the back of the board when possible to spare the electrolytics the worst of switching transients and take some of the flyback edge off.

The capacitor ratings are for the worst case scenario. for ex: a cap rated at 5k hours at 105c and some ripple current will lose some percentage of it’s ESR and ESL capabilities if abused to the max it shouldn’t fail. Nichicon FP caps rated 12k hours at 105c used on some ATX motherboards will last almost forever because they aren’t pushed a lot

@8:50 the hours are rated at the maximum temperature of the cap, typically 85 or 105 degrees C

Not sure why I never thought of that, but using the multi meter on AC to measure ripple is genius! Thanks for the tip!

Perhaps those "unusually small" capacitors are less common for a reason.

Great informative video on ESR caps and how they're different to normal rated caps, thanks for the explanation 🙂 seems the manufacturer skimped on those capacitors due to size they could fit in the enclosure.

At long last, BC managed to get “humping”s into his commentary...and without laughing or missing a beat! Quality.

Very common phenomenon, even in expensive gear. I fixed my £1000 digital mixing desk this way. The trouble is, power supplies are considered commodities and don't receive the same design attention as other circuitry. Also, I found it not as easy searching for "low ESR", instead I consulted the rated ripple current.

In my younger days, I was a coin-op arcade video game and pinball machine tech. I've replaced a lot of those 470µF 6.3V electrolytic caps (most frequently in the power supplies) tell ya what. But not every bad cap was "pooched out" (showing signs of elevated internal pressure) -- some of them looked perfectly normal even under magnification. But *every* pooched-out cap was indeed bloody frickin bad. Wonderful tidbit on using your DMM on the AC scale to measure DC ripple! I'm almost 55 and I've never heard that one before! Thank you Clive!!! :-)

Thanks heaps for the ramble Clive, very interesting stuff. Especially about SMPs and the need for low-ESR caps. I got 3 minutes into this and, when you were saying about if it was a capacitive dropper when the relay kicked in the voltage would drop and I said to myself "then the relay would 'chatter' at 2x mains frequency surely?" Then I had a real "D'oh" moment. I had a set of two RF remotely controlled mains switches and one of them did just that, went into spams when I turned it on and blew the fuses in my amplifier connected to it. I kept it for a couple years in my "NFG" box of things that I might get around to fixing but threw most of the stuff out a short time ago. I figured that my electronics knowledge hadn't got to the level where I could fix most of it by now then there was no need to keep it. However I still have the other RF remote switch on a shelf so I opened that and, sure enough the power supply (for the three ICs, relay and a couple LEDs) is a capacitive dropper run by an X2 cap rated at 0.22uF / 275V. I bet that's all that had failed in the other one dammit! I've been slowly learning electronics, mainly by watching this channel and, while trouble-shooting and fixing a SMPs would have been maybe a bit much for me, I could have fixed that thing after all. The pair of switched mains units and remote cost me quite a bit too and I haven't been game to use the 'good' one since the other failed.

I think the super low service life ratings in electrolytic capacitors apply to the rated temperature. They will last a lot longer if the temperature stays lower, for which reason it's really important to 1) use low esr caps where there's high ripple and 2) design the equipment so that the caps stay well below their rated max temperature.

The logical design of this would be to take the low voltage supply from the router PSU, direct to the relay and to an output socket / lead that would supply the router, then tap off the low voltage to supply it's own logic through a voltage regulator. Thus it would have no high voltage inside it at all and probably need far less rigourous approval regimes.

Great video and awesome insight. Re-capping is a fairly good practice when the replacement of the device is cost prohibitive. I actually recapped some Dell motherboards that had the fake Nichicon E-lytics, because we needed the PC's faster than we could replace them. The fun was unexplainable!

You are brilliant and I second the "like" of when you go off track - so many clever hints and tips. Could you one day take a look at an old audio amp and cure the humming. Would love to see you explain the bits and bobs and give more tips on something more complex.

Very interesting, especially the part on the capacitors. I understand now why the secondary ones suffer much more than the one on the primary even if the average voltage is lower.

I've just bought one for those solder suckers and it's brilliant. It's extremely well built and miles better than the usual cheaper all plastic ones you get.

Hey Clive, let me help you with the pronunciation of router. In Australia, rooting is seen as act of procreation. So when you say router as rooter, we Aussies giggle like school girls. But then “humping” and “riding the humps” made my day.

Always learning from you, those are the exact caps I had to drive up to city for, was fixing an old charger for an 18 volt power supply charger I couldn't believe how simple it was transformer then 4 diodes and a cap 4700 35 volts. I soldered it but never tested it yet. I bought a truck and the kansas rain started up then the flood now its drying up now I just got replace the trans then maybe I can get back to my electronics stuff. I needed a break from automobile stuff. Cheers sir BigClive have a good 1

Back in the early 80's, I was a TV cable technician. A common problem we had with line amplifiers was caused by failing capacitors in the amp's power supplies. Because we have 60 cycle power in the US and the TV frame rate is 29.97 FPS, (just shy of 30 FPS) the resulting interference pattern was a horizontal line that would slowly work itself from the bottom to the top of the picture. Because we were a small company most of our testing equipment was old and the only way we could find which amplifier was causing this issue was to haul around a small battery powered TV set.

Of course the manufacturer/supplier would have told you it was non-repairable and offered to sell you a replacement.

I have no idea what your on about when you go all eleccy gubbins but i find listening n watching you take these apart fascinating

When you said inappropriate components, I seriously expected this to go bang.

I was told by both Bt and Plusnet keep turning a router on and off disables it from the network and it has to be reset by them, so you could be shooting yourself in the foot buying this device.Thanks for the lesson on power supplies very interesting.

I had an Ondigital box, which I bought cheap as OnDigital went bankrupt. But was relaunched as Freeview, and the box worked with Freeview, just some of the menus did not work right but all the channels worked fine. Anyway a few years later the box became unreliable, looked at getting a new one but was a few hundred pounds for a recording Freeview box, so did some research and fixed it. Turned out it was the power supply as the caps where blown. So went to Maplins and bought everything I needed, as you can see still into electronics now as I'm watching this channel.

5:16 “Humps Per Second” - Now here’s a man who has mastered his bit of reality!

Thanks to my limited electronics knowledge and solder skills from fixing things and bit of Big Clive Inspiration. I fixed my own VoIP adapter (HT-502) which had become very nosy. All I did was replace all the cheap electrolytic caps with name brand ones I picked up from a local surplus electronics supply. Total Cost: $3.50 (owned all soldering supplies.) And I have voip adapter that will probably not go bad unlike the last two. One thing that was interesting was some of the new decent name brand caps where bigger even though being the same specs. (HMM?)

Top tip for identifying duff DC power supplies. Cheers!

Big Clive never goes in a wrong direction, just an interesting diversion!👍

I bought a faulty LCD monitor off eBay a few months back for £2, when it arrived it was apparent that it had been taken apart and didn’t even have any screws in it. Straight away I saw 2 caps on the power supply were blown/bulging so I found some the same (on an old but working sky box power supply), soldered then on and it works perfectly. Put it back together with some screws I had knocking about and she’s as good as new(ish)! 👍🏼

back on the farm as a young lad, the crt tv would start to round over and shack at around 4pm for two hours. I check the voltage and it would drop down to 90 volt, I'm in Canada where the voltage is 110 to 120 for outlets and light, 220 to 240 for big stuff like pumps, stove and heat. at my new home the voltage is 127 volt, if it get to 130 volt then you are to call the power company. that 254 volt for for the big stuff

I love all your tangential information

8:55 Well, usually, at least in datasheets, the lifetime of electrolytics is spec'd *at full ripple current AND at their rated temperature* (85/105C). The rule of thumb then is that the lifetime doubles for every 10C lower than their rated temperature. 2000h 85C = 4000h @ 75C = 8000h @ 65C etc.

I had two TP-Link WAPs that were quite good and they both failed fairly close together and I initially thought a power surge had done them in. Opened them up to find the common chinesium type _round top_ electrolytic capacitors. The most expensive cost was the bloody shipping but they both returned to the land of the transmitting for a parts cost of less than AUD$1.50. Nice fix and they will both find a good home(s).

Another useful video Big Clive! Thanks.

Big like for the correct pronunciation of "router".

A ROW-ter is what you use for woodwork. A ROO-ter is what you use for the internet

does Matt want it back after the right sized caps are placed ?

11:28 I liked that direction 👍 (The tid bits of info you’d only get from pro’s are great)

I've used a similar device in the past from another OEM (Aviosys) to remotely power-cycle one of my home servers in case of a complete hang. It was not cheap (IIRC, the single outlet version was about 150 EUR), but it really helped me out many times until I got the server to run stable. There are versions of these devices with several individually controllable outlets as well. These things are essentially little computers controlling one or more relays. @9:24 Electrolytic capacitor hour ratings are specified for maximum rated temperature (usually 85 or 105 celsius). Since most capacitors run at much lower temperatures than their rating, they last much longer.

The capacitor MTBF/hours rating was typically based upon operation of the capacitor at its absolute maximums of temperature, frequency, ripple, and voltage. Reducing any of those factors to well below the absolute maximum values will significantly extend the MTBF...which is why well engineered devices are usually pretty conservative in terms of reducing ripple, peak voltage, and operating voltage so you get a greatly increased MTBF. Also, older electronics tended to be more tolerant of ripple as well, which also means that they tend to tolerate more degradation of the capacitor before they cease to operate. If you download a major brand name in aluminum electrolytic capacitors they will often have some guidelines for estimating capacitor life when operating at less than the absolute maximum ratings.

The advert I got for this video was a man that says you can bring any dead battery back to 100%

My goto for replacing old electrolytics in electronics are generally Panasonic FR's - low-ESR, decent quality and available in loads of sizes, even smaller ones (they're not the cheapest though). If I recall correctly Würth also make low-ESR compact designs. Sure, they're not Japanese (like Chemicon, Rubycon or Sanyo), but they're at least decent - especially compared to many of the Taiwanese caps. Shame there's no such thing as a perfect cap, if you're going small in size, you're generally compromising on something else. (Mind out of the gutter!) Be it cost, quality and/or capacitance/voltage.

This video explained my broken psu I spent a few weeks on before I ended up cooking it :(

My old PC used to crash randomly and blue screen or just do weird things in general until I got fed up with it and stripped it down to clean. Looking carefully at the motherboard I noticed 2 clusters of 4 caps near the CPU, they had bumpy tops so I ordered a load of the same type/values and replaced all the electrolytic caps on the motherboard and it worked perfectly after (and still is many years later). Don't be afraid to replace the caps on a motherboard, just be aware of where they come out on the track side and the polarity, don't linger the soldering iron too long on the tracks and be careful of bridging tracks. There are some wiggly tracks near the CPU pins which are for timing the data lines and the caps are close to them. Just take your time, take it slow and careful and give it a go :D

Clive, i've come across the problem with caps several times before.I just replace them with metal encapsulated SMD ones. Simply remove the rubber foot from the bottom of the SMD cap and bend the legs slightly in order for them to fit into the holes on board. Maybe a touch of heatshrink over the top. Of course it helps if you have SMD one's in first place in the correct values I suppose

The 2000h number translates to something like "after 2000h at 105c ambient temperature, the capacitor's will be within 30% of its specifications" (or some percentage high enough) as in it will degrade significant enough to be outside specs but will still work. Also, with electrolytic capacitors, a basic "formula" says that lifetime rating doubles with every 10 degrees Celsius , so if the temperature inside the box peaks at 95c , then capacitor is rated for 4000 hours, if below 85c you have 8000 hours and so on. For polymer capacitors, formula is changed a bit, a simplified version would be L = Lorig x 10^ [(Tm-Ta)/20] ... so a 2000h polymer capacitor running at 70c average would be rated for L = 2000 x 10^(70-30)/20 = 2000 x 10^2 = 200.000 hours. You could get some 270-330uF 10-16v polymer capacitors and replace the electrolytics, it will work.

Hi Clive, watched countless number of your videos and thoroughly enjoy your stuff! Question... How do we send you an electronic something that's broken so you can take it apart, find out how it works and why it failed? Thanks

Great video as always 👍

Going off in a “random direction “ can be very informative!

You had me at “inappropriate”! ❤️

I had a cheap SMPS which failed due to the output diode (a heat-sink mounted TO-220 package) coming loose from the heat sink and heating up until it went temporarily short, which blew out the output filter capacitors. The primary control electronics had a current-limiting feature, so the diode actually cooled back down and stopped being shorted, but the caps were still toast. I didn't think it was worth fixing, as I only paid $9 for it and it was already several years old, so I installed some non-low ESR "JWCO" caps ("JWCO" makes both low-ESR and non-low ESR varieties) that I had on the bench to see what would happen. It not only started working again, but has been working still for the last month, with a lot of very hard service in high-temperature conditions. The output ripple is minimal, as well.

There's no better way to start your day than Big Clive videos, a bowl of nuggs, and enough caffeine to kill a horse.

It really frustrates me that consumer-grade routers/modems/Internet connections are so routinely unreliable that products like this exist and people "rebooting the router" is such a common thing to happen or to hear about. I really don't think it has to be that way... :( Since mid-2013 when I moved into this house and became responsible for our Internet connection (at my previous house, my then-housemate had that job) I'm fairly sure that I've only ONCE had to reboot a router or modem to restore service. We have two VDSL2/FTTC 80/20Mbps lines here, each connected with an ECI B-Focus modem ( kitz.co.uk/routers/openreach-modems.htm#openreach_modem ) of the type supplied by BT Openreach during VDSL installs in the early 2010s (although only one of mine was supplied by BT; I bought the second from eBay to ensure that both lines were the same and because that ECI modem is/was well-regarded). While the ECI modems are probably partly responsible for the high reliability of our connectivity, I think that the primary responsibility lies with our MikroTik hEX, aka RB750Gr3 ( mikrotik.com/product/RB750Gr3 ), which is admittedly not a very consumer-friendly device for configuration, requiring a fair amount of networking knowledge to configure (they have a demo system you can play with here: demo.mt.lv/ ). But it's very stable hardware and software, and not even expensive - the RB750Gr3 retails for less than £60: linitx.com/product/14919 That doesn't include a modem or a Wi-Fi access point, but a lot of more technically-minded people prefer to have those as separate devices anyway. Modems should ideally be right next to the point where the telephone/coax-cable line enters the property, as extending a telephone line BEFORE the modem will usually drastically reduce the attained Internet throughput speeds, and Wi-Fi access points should be positioned with respect to the layout of the building, the construction materials used, where Wi-Fi coverage will be most needed, etc. - and you may even need several access points to achieve good coverage in a building that's large, has brick-built internal walls, or has heavy interference from other devices or from neighbours. Not only is it unlikely that the modem(s) and Wi-Fi access point(s) will be best-positioned in the same place, but there's also no reason for the router itself to be anywhere close to either of those. In fact if, for example, you have a cluster of Ethernet-connected devices in one part of the building (either desktop PCs, games consoles, network storage devices, etc.), you may want to have the router nearer those - or maybe just an Ethernet switch for those devices, with a cable running to the router somewhere else entirely, would make sense! In my case the modems are by the front door, with Ethernet cables running two floors up, through the stairwell, into my "networking closet" which houses the router and the core 24-port switch. Then the main Wi-Fi AP is also in the stairwell, so there's a cable running back to that.

Clive i think it was when they were run at their max rated temp. Eg 2,000hr @ 85°C As I have seen the same ones rated 20,000hr & 35°C

For the estimated life of a capacitor at a lower working temperature, every 10c below the max temp you multiply by 2. So a capacitor with 2000h at 85c if it works at 45c will have 32k hours estimated life, about 3.5 years (perfect for warranty..). As for the capacitor replacement you could probably use a 6.3v as the psu out is 5v. Usually they round up the voltage value of the cap if there is a headroom, in this case about 25%

Hi Clive, I'd suggest leaving larger sized capacitors if they can fit in the box. Browsing datasheets I've mentioned that often differently sized electrolitics of the same type and capacity with smaler diameter have shorter lifespan even in the lists of reputable producers.

Those low cap life ratings are at full voltage at maximum operating temperature. if you run them at lower temperatures, the will last a lot longer. same goes with lower voltage.

Capacitors are super reliable. Cheap SMPSs often use less capacitance than needed, forcing them to run hot from the ripple current.

Had exactly the same with a Perrin and Rowe instant hot water tap. The PSU uses a resistive dropper with a 100uF cap across the bridge, driving a relay via an electronic thermostat. Problem was the 100uF was adjacent to the dropper resistor and the heat dried the cap out, the unit appeared to power on, but as soon as the relay energised it turned off again. Fix, replace the cap and mount it away from the dropper resistor. Just a badly laid out circuit board. I've let them know my thoughts.

The capacitor closest to the transformer would see far higher ripple currents than the capacitor after the inductor. Also when they dry out from a leak, the ESR increases and they get even hotter and the process runs off much like thermal runaway. On a side note the capacitance usually goes up more when they dry out but they become less effective at filtering due to the internal resistance increase.

9:25 the lifespan provided by the manufacturer is specified at the maximum rated operating temperature (85°C, 105°C, or even 125°C, depending on the capacitor.) As you lower the ambient temperature, you effectively multiply the cap's lifespan. If I'm not mistaken, for each 10°C drop its lifespan is potentially doubled.

As I understand it, an electrolytic capacitor's lifetime rating is based on conditions of its own maximum electrical and temperature ratings. To make a capacitor last far beyond rated life, one simply "over-rates" components; runs them at well below rated maximums. For instance if it's to be run at 85C and 10 volts, use a 105C/16V cap -- or better.

THANKS for the extreme zoom! You're the best! Excellent tutorial on capacitors.

I rather wonder if the failed capacitor was simply labelled for a higher voltage somehow. Not uncommon with some dodgy manufacturers, unfortunately

I thought it was funny 😄 that you explained the word “banjaxed” 😆 (me taking that word for granted as I’m in the U.K. & then realising folks in other countries might not understand the reference) 🤗

The second page you printed out looks like a misplaced description: I can't find an "AM" series on Panasonic's site, and the details on the page point at their "M" series which is just a general-purpose 85°C capacitor, nothing remotely special. Panasonic do have a suitable capacitor in their FR series, if you can obtain that. Other series with 470μF in 6.3mm diameter include Nippon Chemi-con KZN, KZM, KZH, KYA; and Rubycon ZLH, ZLJ, ZLQ and YXJ (the latter two in 10V, even!).

Those smaller sized electrolytic caps seem to fail more often than the larger ones of the same rating. I guess that they are somewhat optimistically rated. Looks like the swollen unit was closest to the diode so may have seen some heating.

Alternatively, you can tear down your D-Link router and salvage some components, and invest in a real Router that doesn't crash every 30 minutes

Hi! I'm currently making myself an order for recapping some stuff (monitor PSU and an ATX PSU), very good explanation about why low ESR caps are needed. I was wondering, what kind of values is considered low ESR?

Great video clive

I thought you were going to finish by saying "I'm Scott Manley... Fly Safe" you two could be brothers :-)

I wonder if there are any funky security exploits on the networking side...

For some reason, cap failure seems to be a problem in modern flat screen displays. I've picked up a few dead ones and, for the price of a few new caps, I have good working screens.

Can we all appreciate the guy who removed the security screws, those things suck!

I learn so much from you, how's the TT going btw?

"Wrong direction". Love it.

I've got capacitors from the 40's that are still working fine, they're dry electrolytic but there's no hum in my amplifier, I actually installed it because I wanted it to look old inside, but there's no hum at all, it's really silent, I also used old bypass caps too, no leakage at all

As suggested below the lifetime rating is at maximum everything, temp, voltage, and ripple. Drop these by a few percent and expected lifetime multiplies..to the extent if you are careful in your electrolytic choice they will last almost forever. (forever being 30+ years).

Replacing output capacitors on a smps can cause issues if the esr on the replacements is much lower than the original, considerably lowering the esr will increase the Q of the output filter, and can affect the frequency response of the system, making the supply unstable.

The life rated for a capacitor is the life of the capacitor at the maximum rated temperature for which the capacitance of the capacitor does not drop below a specified amount. Generally running a capacitor at 10 degree lower doubles the life time. Note this almost means that if more capacitance that needed is used capacitors may be out of spec but still work due to the over design.

Clive, if I'm recalling what I learned exploring all the different Cap ratings Mouser lists that MTBF on the cap is for its time to fail at (above? percentage of?) the specified temperature. So 2000 hours of operation during peak temperature plus (if I recall) a much longer duration under normal stress. Couldn't see if anyone noted that; no search in this interface!

Ahhhhh. Nothing better after a long day than a cold IPA and a Big Clive Video

The hour ratings depend on the temperature. They will be rated 2000 hours at 105c (or whatever their temp rating is), and they last a lot longer at lower temps.

10:58 I used to work in an electronics service company, about 12 years ago. I remember there was a certain Samsung STB model that had its PSU fail a lot. It was a ripple problem and was corrected by replacing the larger cap plus soldering a small some nanofarade cap across it.

Love those "Off Label" mods .. .. ..

Root is a subterranean plant support structure.

Capacitor life de-rating is something all electronics degree courses should cover but frequently don't. Many consumer electronics companies have been caught out.

I need to get something like this. I know there are software methods available, but I’d rather have something physical as it will be easier in certain situations.

There are electronic cabinets in the industry running electronic equipment continuously for 30 years, those capacitors are running over 250.000 hours. About 4 years ago, while attempting to repair a system (pre PLC/DCS era) in a power station, the cabinet had about ten 24Vdc power supplies, two had failed, switching off the cabinet and substituted the two, simply switching on the cabinet, another two failed.

I would expect the one next to the transformer to fail first, not from heat from the transformer, but from heat generated by the ripple it's absorbing. The downstream one (after the inductor) would see a lot less ripple current, and be subject to less self-heating.

BTW. If you don't have low ESR cap you need, solder low value ceramic cap in parallel with a regular one on the other side of the board. Its better than nothing.

The lifespan is coupled to the temperature. They usually have a graph but for simple specification they just give life expectancy at its rated temperature. Better quality caps will be 135deg C but these are expensive.Another way to improve things is to use a higher voltage spec. but that will result in a larger capacitor and also higher price. 2000hrs at 85deg C would probably equate to 20000hrs at 40deg C.So keep your power supplies cool and they should last a long time.

KZfaq auto captioning is convinced you are talking about "crack pastors". I just found that amusing enough to share :P