In my experience, after a basic capacitor check, the next likely components to fail are actually diodes. I'm a bit like you in a sense that I repair gear on a regular basis so I tend to see this a lot. When I see a diode failure, I usually make a time-saving assumption that the selected part may have been underrated and use a more beefy diode, respecting the switching speeds of the old part of course (naturally, it's also possible that the degraded circuit was pushing higher than expected current through the failed diode...). There are complex situations when you're forced to actually go through the schematics and evaluate that yourself, but often I deal with broadcast and scientific gear that has thousand page service manuals and generally complex and elaborate operation.. so the easiest thing is just to select a similar but higher rated part. I always get capacitors/diodes/transistors from reliable sources for the same reason. Thank you for explaining that circuit, very interesting and helpful!

I love video's like this. Taking a $5 supply, troubleshooting and repairing it. Sure, you can go out and buy a new one and not waste your time, but you can spend a couple days and learn stuff and repair it. A lot more fun.

@bigclivedotcom

7 жыл бұрын

It would definitely have been cheap to replace, but fixing things is like an enjoyable puzzle.

@iceberg789

7 жыл бұрын

any suggestion to fix if the coil is cut in the transformer of an usb charger ?

@SigEpBlue

7 жыл бұрын

+iceberg789 I'm not trying to discourage you, but.... Odds of fixing the fine enameled-copper windings are near nil, unless the break is right at the very end where it joins the terminal. If you can find a near-exact replacement transformer, either new or salvaged from retired equipment, it should be a simple swap operation. The trouble is that you need to know the _exact_ specifications of the _original_ transformer: dimensions, number of windings (usually just primary, secondary, and then feedback and/or bootstrap), voltage ratio (a.k.a. turn or inductance ratio), etc. Sometimes you can get lucky and find the model number on Octopart, but more often than not, they're made in-house and don't have any numbers.

@HelenaOfDetroit

7 жыл бұрын

Cut in many places or just the 1? Also, primary or secondary coil?

@iceberg789

7 жыл бұрын

at the primary side, the ground pin of the transformer doesn't give short sound to any other primary or secondary pins. i guess its a goner.

Very good BigClive. The first thing I thought of was caps. Input, and one on chip just as you did. Exactly as you did was second I would have done, re-solder the transformer pins. I did suspect the diode as its breakdown voltage was deteriorating. Once you found that, yes it was fixed. What I learned in this is your use of a IN4148! The output current passing in one of those is very small, yet the chip did not need much current. Thanks for that as I would never have attempted to use the IN4148 but it worked on this because the current needs are very small. Glad you got it fixed!

Damn. Clive you are really good in terms of electronics. I'm still learning from you so much.

Big thanks to you Clive! After following the steps you took in this video, my LED downlight now works properly. All I did to fix it was re-flow the solder on each joint and add a bit of solder if I thought it looked a bit lacking. Light output is now rock solid!

@jeremykemp3782

Жыл бұрын

Is there a preferred solder to use over others? Thanks

@Tommyinoz1971

Жыл бұрын

@@jeremykemp3782 Yeah, lead based solder is usually the best.

@jeremykemp3782

Жыл бұрын

@@Tommyinoz1971 thanks

@jeremykemp3782

Жыл бұрын

@@Tommyinoz1971 flux pen?

big thanks Clive been scratching my head over some strobing led strip lights till i searched online and came across your video. Now sorted fantastic help.

Thank you Sir, you have literally become my electronics tutor nowadays......always learn a lot from your videos......

Stubborn! Much easier to replace the component, but we are all enriched thanks to you not taking the easy way out. Brilliant

I've got the same problem with a flashing LED downlighter. It's driving me mad removing one component at a time and testing them. I'm glad I remembered Clive making this video. I'm now heading straight to that bootstrap diode!

Clive, one of the best troubleshooting tools I used to carry, was a can of freeze spray. I found it quite handy for intermittent issues like this one.

Absolute genius video - EXACTLY the same thing happened to me and I'm now inspired to attempt a fix myself rather than throwing away...

Thank you so much! Switched "50 kHz fast diode" to 1N4148 and it works now. No "bathroom party" strobing since Wednesday :)

just got a a basic understanding of a simple switchmode supply , thanks Clive.

All this technology and you can't beat good old switch-start fluorescent for reliability :) The under-shelf lights in my kitchen have been re-used in subsequent redecorations since the early 1970's! :)

@bigclivedotcom

7 жыл бұрын

Absolutely. Better lumen maintenance and reliability than LEDs.

That startup arrangement is used on lots of supplies, including PC ones. Many's the supply I've fixed that was fine "until we moved it/had a power cut". Most times it's the cap that's been cooked, but the resistor is often under-rated on universal input voltage ones - it's OK at 110V but not 230V.

Nice detective work Clive! Glad to see you're back home in your own laboratory (always the best place to be) I hope you'll be doing some more 'making' videos soon, to educate and inspire us electronic noobs. Thanks as always!

@bigclivedotcom

7 жыл бұрын

I do plan to "make" some stuff.

I KNOW NOTHING ABOUT ELECTRONICS, BUT LOVE ,ALL, YOUR VIDEOS CLIVE, FASCINATING , . STARTING TO PICK UP BITS AND PIECES, KEEP THEM COMING. TAKE CARE.

Another great video and your such a great tutor to learn from and so many on youtube to choose from.. You are our NO 1.

Excellent stuff, Clive! Thank you!

With the help from this video, just fixed an expensive power supply that had this exact same symptom. All I did was replace the bootstrap supply diode and that fixed it. It tested OK using a multimeter but must have been breaking down under high reverse voltage peaks. Thanks ;-)

This video rocks. I would never have guessed the diode. I was sure it's the driving chip. Thanks for sharing the knowledge!

YOU ARE A SAINT! Aquarium LED strobed... would be > $100 to replace. Replaced all caps didnt work...was about to give up came across your video and looked at an HER107 diode... measured OK but I changed it to a HexFred I have handy and voila it started working again!!! THANK YOU!!!!!!!!!!!!!!!!!!!!!

Thats the real problem in a driver ckt.we always test the electrolytic or ceramic capacitor and ignore the test for fast recovery diode. Thank you for your contribution in this field.

Allways enjoyable to see you repairing switchmode supplys, a nice cute supply as well :-D. That chip may be a copy of a topswitch design. Clive, im glad im not the only one that has red herring repairs, it can be so dam annoying when the second you turn your back, its dead again lol.

Nice video Clive. Love it when you have to take us through all possibilities! And apparently there are still videos I haven't watched 😄

Great explanation of how the circuit works!

Darn...I was waiting to see the "Hammer of fine adjustment" get used....

@annelisemeier283

7 жыл бұрын

Same

@ollieb9875

5 жыл бұрын

AKA the bench x-ray 😂🤣

Excellent debugging process and repair.

That's a weird-ass failure mode for a diode. Thank you for posting your fix!

That was such a great lesson, so thank you BC.

Impressive electronic skills!

Interesting and clear explanation (as always) Yep rare for the bootstrap diode to be intermittent even on cooked smps

When I read the title I thought you were going to repair a CP stormy or Atomic led power supply :D Anyway, like these video's just as much as the ones with PRG equipment.

Another great video. Thanks for sharing.

Dam.. I was hoping it was a simple retouch fix so I could recover a flood light. I'll just have to go with the original plan and swap for an IC type. You always do great work. Thanks

@fruitichunes9913

5 жыл бұрын

It’s really simple to fix you need a item called a glowfix or a yagf Put this in ebay to ebay search bar to see what I mean 293128500853

Have you ever thought about putting an album of bedtime stories out? Mothers would love you. Your soft voice and gentle,scotch accent would put any child to sleep. Sometimes it puts my wife to sleep. "I don't understand a word that he is saying, but I love his voice." Then she nods off.

Somethings I think it would be great if you had a scope Clive. Would help the investigations on some of these failures. Sadly not unheard of for these diodes to fail

@JonaJona

7 жыл бұрын

I also think showing the actual waveforms on the circuitry like mains, rectified mains, smoothed rectified mains (/with bad cap) and generated switching voltage could help understand the circuitry. I have an old analogue scope myself and it not only (obviously) helped me solve a lot of problems, but also really showed me how stuff is working. Just an idea that just came to my mind: Probably Clive has one too, but maybe an analogue one and can't film it due to the flickering.

I'd replace it with another 1000v part like UF4007 if that's what they used, you'd be surprised just how much reverse voltage all of the diodes in a flyback power supply have to withstand (including the secondary rectifier). The 1n4148 is only rated for 100v and could fail from over voltage at some point down the line.

I learned a lot from this one, thanks!

Hi, I'm an old tv engineer from the 70's and much of our work was similar to this, problem solving, and again it was always the last thing you tried! Frustrating when you have an old bloke sat opposite you in an arm chair waiting to watch the news and his wife plying you with tea and cake..... those were the days......

@rickyreynolds17

7 жыл бұрын

Last thing you tried?? Lol I personally wouldn't find the fault and carry on looking :)

@vivianfrancis2391

7 жыл бұрын

Haha :)

@superdau

7 жыл бұрын

Of course it is always the last thing you tried! You wouldn't keep looking for a fault after you fixed it! ;)

very useful dissection lesson of the LED driver circuity.

Nice diagnostics!

Thank you for the thorough explanation.

Dear..., thank you very much, I was helpless! Exatly the same issue, the same diode. I changed it and it works! Thanks, thanks, thanks!

I love your perseverance, I would have thrown it in the bin and cursed technology after the first attempt :)

great video thanks for the information on the diode.

Thank you for this very educational video! :)

I was hoping "flashing content" meant we would see what puts the big in big Clive.

@rockstopsthetraffic

7 жыл бұрын

I laughed more than I should have.

@rockstopsthetraffic

7 жыл бұрын

I laughed more than I should have.

@aaweso_me5200

7 жыл бұрын

LOL

@SeanBZA

7 жыл бұрын

That would have been a lot of red beard coming into frame as Clive got more excited as he was working on the board.....

@SigEpBlue

7 жыл бұрын

Some were disappointed, many were relieved. :)

Glad you solved it, I still have the problem without knowing where to buy replacement parts if I can at all

Hi Clive - I have the flashing light issue in a chandelier containing 18 Disc shaped LEDs each with 6 yello LED Pads. Anyway I thought just to swap out the driver. When I removed the chandelier driver compartment I found two drivers. One was 240V 40W DC 12V 2.5A and the other 240V 30W DC 12V 3.33A. I don't seem to be able to find precisely the same spec drivers on the web. What sort of flexibility in spec do you think I have for example would it, like as not, be OK to use a 100W 5A 12 Volt LED Driver to power the lot? Thanks

I know fuck all and I still watch these videos - very much like watching the open university on BBC2 in the 90's at 2am

I see a lot of outdoor signage and even sometimes outdoor parking lot lighting strobing, maybe about once per second. I live near Toronto where winters are quite harsh. Goes down below -18C or 0 F sometimes. Does the cold make these things prone to fail?

I had about 15 of these when I replaced all my track and accent lighting in house. After about a year I think I lost about 70%. None were being driven past 50% of rated wattage. I never bothered opening them to find out why just replaced them all with higher rated units. So far it's been a year and half and not a single failure.

@randomvideosn0where

7 жыл бұрын

For mine I bought a few of those 20A 12V (ish) power supplies off ebay and ran a ton of 12V wire, the smaller ones never seem to last.

Lovely , keep up the good work

good man thinking of people with photo sensitive epilepsy!

Cost of an LED driver, a couple of quid, the value of the time spent repairing it £100, the humour of BC finally getting to the diode, priceless. It's always the last place you look!

@rockenrilijus

5 жыл бұрын

Value of the time depend in which part of the world u are. By fixing u reducing electronic waist and there is a job for man who is fixing it.

Hey Clive, sorry I didn't ask yesterday, but are you looking for an ESR meter? Very handy for checking capacitors, many times while still in-circuit.

thanks Clive for the information

Good timing this video. I have a similar problem with my LED transformer. It doesn't cause the light to flash, instead I get random intensity in light. Its only a month old and I've already pulled the circuit board out to inspect it for any obvious issues but I'm not an electronics person. Ill try some of those things you showed in the video.

Hi Clive, i have replaced more than 20 set of led driver and ceiling light rated 12w in my house. I felt it was a waste to throw it away everytime i do ceiling light replacement and i am glad to find this video. i have checked one of the led driver which should have give a DC output of 28v-43v with constant 300ma current from 240v AC but when i checked with multimeter it shows small reading in mv of DC but when i change the meter to read AC it gives about 8v of AC. Can you please advise me on how to fix this or i should just throw away all the driver? I was thinking to reuse the good component between the driver.

Same fault plus low voltage when it came on.I replaced a bulging output cap and what I suspect is the same bootstrap capacitor even though it's tested ok. Amazingly the psu works now ! Nice 4a psu and mini fridge for 50 p 👍

Wow you seem to really know how these things operate. I have three led shop lights that have a dim high speed flickering. I do have some basic knowledge of components typically seen on control boards, So I thought I'd take a look at it. I was surprised at how much was involved in just turning on some leds. Problem is I had to de-solder the low voltage wires connected to the led strips so I could access the board. I did some testing with a meter and didn't find any obvious problem yet. I then tried to check it live and one of two capacitors at the end of the circuit blew up and smoked. I had not touched anything yet. Did I cause the failure due to no load on the circuit or did I exploit the real problem? any advice would be appreciated...

His voice is the best ASMR

Certainly could do with a 'flashing lights' warning in the description - and while I was typing that you added one. The debug technique makes a lot more sense since I re-watched your excellent basic components outline yesterday. 8-)

more of this thinking aloud and not giving up until it is understood and fixed...thank you

Thanks for sharing, i definitely learnt a thing or two.

Thanks Clive I know it was a pain in the ass to fix but valueble tips for us :)))

My spidey sense was tingling when you said the solder joint looked strange. I think the diode went bad (excessive reverse current), got hot, and started to desolder itself.

Hi Clive, i have a pir lamp for outdoor with two 6w led lamp on it. One have this flashing problem when i bought it and died few week later... I open it and the led driver are lot more complex than this one on your video. i have tested the majority of components, the only thing i have found is a optocoupler (4pin chip) installed in wrong polarity from the factory. But the led driver still not work, the optocoupler is fine because i have tested it in the other led driver. This mistake from the factory have caused another trouble, But I did not find it. Do you have an idea what can be the problem now ?

I have a slightly different problem in that my LEDs flash on-off in a regular way. They keep flashing for a few seconds after you turn them off. Any idea if this is a problem with the power supply or if it is a loose connection somewhere? Some of the LEDs don't light up at all so I wonder if this is the issue.

Thanks for this vid.... I love it. Cheers

what would happen if you would try to dim a LED with a driver like this using a PWM dimmer?

Hi I wondered if you could help I just replaced my 8ft tube with an LCD one and it would 'nt come on to start with then when it came on it would stay on a while then flicker it's on the original ballast and LCD starter

Excellent video, as always... However.. the pedant in me would say, albeit with a smile on my face... that the last component to be checked is always the one that solves it.. If only because 99% of us stop once it's working again :) thanks for all your videos Clive, I truly do appreciate you putting the time in and enjoy every one.

This guy's brain is set on genius mode

it'd be great if you could explain a bit more what the "bootstrap" module does... whenever you have the opportunity!

I'm having the same problem and while the board layout is different it sounds like the circuit construction is the same. Since I'm too lazy to try out every other component like you did, I'm just going to try the diode first.

Have you ever had led light flicker. Even flashlight led powered by batteries. Are led lights sensative to rf or emf when they are made in arrays or Cob style surface mount cob style

So, what did we learn today? Always have a can nearby to cool down before testing?

Hi can you help me with a problem of mine? I have a LED strip installed in my ceiling and it has a small square black driver with a single button on. The button is to change the program of how it pulses. Problem is i have to press that button everytime i cut the power to the strip to make the light solid or else it will cycle through every single mode and its driving me crazy. Please help me. How do i make it stay lit solid after i turn it off and on without the need to press the button on the driver. Is there anything i can remove from the driver?

I got a newbie question. Why not use a capacitive dropper to a bridge rectifyer to a smoothing cap?

another great video

Your 'flashy' new kitchen!

I have a set of these drivers, one on each led, they start to flicker in sequentially, start with one then then another.... Predictable start from one then the next.... Follow the leader, they are 12 v led, the drivers are old, but seemed to be OK with the halogen units, spend a few £ on the led, yeah should have purchased 240 mains led, any advise or has it happened to you,

Repairs do have a fun factor👍

I have just had the very same strobe problem on a new 80 watt LED flood light. I took the driver out (only after the supplier said they are sensing a new unit and not to bother returning the dud) Trouble was it was fully potted so it got binned and a replacement drive unit is nearly as much as the lamp.

nice fix

I have a question i have a power supply issue the only time my leds work is when i apply pressure to the lights idk whats going on

Had exactly the same issue, flashing light, with the same type of diode in a different model power supply. The problem only appeared after the power supply warmed up, it was installed in a roof space with a metal roof (after 5 years of use). Tracked down the intermittent problem using a hair dryer and a can of freezer spray. Easy to say just replace the power supply but the customer has 80 lights with the same power supply, total replacement cost (try & find the equivalent/same power supply!) was NZD 3,200. Cost of the 80 diodes was NZD $12 from Aliexpress.

A year or so back, I ordered a 50 watt LED that came with a power supply sort of like that one, but undressed as you have it now. It never did work, simply flashed like that every time I had it hooked to anything. I never have tinkered with it, as I don't like playing with mains voltage, even with our little 120 Volt here in the US. I think I still have it laying around somewhere, perhaps the next time I run into it, I will at least try the re-soldering of the joints. I did that on the back up monitor in our motor home this spring, and it brought it back to life, there was some very poor solder joints, I was surprised it ever worked properly but it is the one that came in the unit. They get a lot of vibration when mounted in the dash as this one is. After re-soldering the joints, not only did it come alive, and stay alive, but I discovered that all the controls had red LEDS that lit them up, none of those ever worked before either. Now I can keep an eye on our Jeep Liberty as we travel the highways and byways of our little country.

@bigclivedotcom

7 жыл бұрын

It would have to be hooked up to its matching LED style. If you used it with lower voltage LEDs it would interpret them as a short circuit and do the pulsing thing for protection.

@paulstaf

7 жыл бұрын

I bought this off DealExtreme: www.dx.com/p/330ma-9w-led-constant-current-source-power-supply-driver-90-265v-81779#.WMDQNLkrLGI I hooked it up to some COB light bars that I have and it just flashes exactly as in your video. I bought TWO of those supplies above and they both do the same thing. I run the COB lights on another CC supply at 32V 500ma so about 16W or so, do you think that that may be overloading the Chinese 9W supply above? I also have some of those "10W" 'garden' lights like you always show in your videos that only put out about 6W, so maybe I'll try running one of those off that 9W supply and see if it works. Great videos btw, I love LED lighting!

@bigclivedotcom

7 жыл бұрын

Those power supplies are designed for LED arrays rated for around 30V. What voltage are your COB bars intended for? It may be that they are pulling the voltage too low and causing the driver to shut down. It's possible your other driver is capable of handling the wider voltage range.

That is interesting, I have a power supply in an audio amp that was bad and it is a common thing to blame capacitors. I did, but when probing around with my dvom I noticed that I had three bad diodes and one bad resistor. I don't have a schematic and so I am having trouble figuring out the diode values as these are Zenar diodes.

I remember seeing something similar to this on an LED lamp that was designed for outdoor use.

You and Tim Rowett from Grand Illusions should team up to make a video together. He would present some toys and you'd take them appart and explain how they work. That would be the most interesting and relaxing video on KZread :)

Had exactly the same fault with 1,5 year old LED-Panel driver! Thanks to this Video I fixed the RL207 with a FUF4007 from an old TV-PSU! The Diode beeing too close to the heatsink seems fault related...? Anyway thanks for the video ;)

Here's to perseverance *raises glass (or can of irn bru in my case)* This pretty much mirrors my experience over the last few weeks trying to fix a zx spectrum - replaced nearly every bloody component on the board (turned out to be the ULA)

interesting way of thoughts in problemsolving

Dear Clive. I have a question. I have modified an led-series driver into dimmable with simple parts (13005 + 50k potensio), and it get flickered when in middle brightness, but fine when in the lowest / highest turn. How to make the mid turn not flickering with simple parts? Hope you will make tutorial from this.. 🙏

Hi, I've got a 3LED garden light that I have recently looked at due to not working. I assumed it was the battery, which had leaked - possibly due to water ingress. Found out that it was not the battery, not the switch (the switches in the lights can be temperamental sometimes) and not the solar panel. I'm guessing it is the control chip, which is a CL-0116. Any ideas on where to get the chip from, or how to test the chip to see if it works? Also, if Clive wants to have a look at this light, in the hope of repairing it then he can do.

@bigclivedotcom

7 жыл бұрын

It's often corrosion that damages the component leads. Easiest fix is to get a cheap solar light and transplant the circuit board into your favourite one.

Hi Clive, good video's by the way. when you have time, could you do a video on the l7912 -12v regulator. much appreciated has I am new to electronics, I know all about all other components. it's just the l7912 and other l79**, I just can't seem to get the layout right. many thanks!

@bigclivedotcom

7 жыл бұрын

The main things to note about the 7912 regulator is that it is a negative rail regulator as opposed to the more common 7812 which regulates the positive rail. The pinouts are completely different and you have to keep in mind that the metal mounting tab is connected to the middle pin, so if you mount it on a heatsink with other components then the tab may have to be isolated from the heatsink with a suitable insulating kit including the little insulating inserts that go into the holes.

part of the crew, part of the ship :o)