(Flashing content.) Repair of strobing LED power supply.

[@oriole8789]

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!

[@clony101]

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]

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

[@iceberg789]

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

[@SigEpBlue]

+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]

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

[@iceberg789]

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.

[@Tommyinoz1971]

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]

Is there a preferred solder to use over others? Thanks

[@Tommyinoz1971]

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

[@jeremykemp3782]

@@Tommyinoz1971 thanks

[@jeremykemp3782]

@@Tommyinoz1971 flux pen?

[@Electester]

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

[@tasmedic]

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!

[@anthonyselby8337]

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.

[@shiladityaray3137]

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

[@Graham_Langley]

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.

[@EyesOnReality]

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!

[@jeruharlem]

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

[@RobertPyeUK]

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

[@FrontSideBus]

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]

Absolutely. Better lumen maintenance and reliability than LEDs.

[@CodyTreng]

The LED lights in the our house I replaced the switching driver modules with good old 60Hz transformer + bridge + cap. Less efficient yes, but with just 3 parts they're much, much more reliable than modern switchers. They're still working well after many years.

[@seanet1310]

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]

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.

[@ricknelsonatwork4981]

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.

[@ranjulatanayak584]

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.

[@footstepsinchina299]

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

[@annelisemeier283]

Same

[@ollieb9875]

AKA the bench x-ray 😂🤣

[@uK8cvPAq]

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.

[@andrewbaker4503]

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]

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.

[@magicaardvark1]

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]

I do plan to "make" some stuff.

[@argoneum]

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

[@andrew_radio]

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

[@rockstopsthetraffic]

I laughed more than I should have.

[@rockstopsthetraffic]

I laughed more than I should have.

[@aaweso_me5200]

LOL

[@SeanBZA]

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]

Some were disappointed, many were relieved. :)

[@jameslamb4573]

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]

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.

[@jimarnott9593]

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

[@adrianpearce4567]

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 ;-)

[@1971thegrinsh]

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

[@Peter_A1466]

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

[@envisionelectronics]

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

[@180bst]

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.

[@28gwdavies]

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]

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

[@vivianfrancis2391]

Haha :)

[@superdau]

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

[@johnsonwu7055]

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!!!!!!!!!!!!!!!!!!!!!

[@tensazero]

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]

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

[@JasonDukeSEO]

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.

[@zx8401ztv]

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.

[@rklauco]

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

[@kevinoakes1870]

good man thinking of people with photo sensitive epilepsy!

[@russellhltn1396]

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.

[@zaczac3024]

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.

[@dezzie50]

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

[@GeneralTotoss]

His voice is the best ASMR

[@jimbrideau5802]

Great explanation of how the circuit works!

[@miskatonic763]

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.

[@piktovic]

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

[@q12x]

Excellent debugging process and repair.

[@JerryEricsson]

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]

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]

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]

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.

[@AThreeDogNight]

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

[@happylarry955]

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

[@madinatore]

bigclive would you be interested in a 1.5KW ATX PC 230V power suply that turned to a PC killer and breaker tripper after a lightning strike?

[@madinatore]

well its not visibly damaged from outside

[@bigclivedotcom]

If the PC was dead then it may have suffered from the lightning strike too. I doubt even the best quality PC power supply could keep lightning from getting through.

[@madinatore]

as I killed a new motherboard with the damaged PSU its a killer on its own now

[@akabiscuitwaffle]

annddddd that's why cheap PSUs are refereed to as time bombs. Oh higher quality ones ARE rated for lightning strikes, and so are quality motherboards.

[@madinatore]

guess I shouldn't buy silverstone and MSI/ASUS then eh?

[@wileymarm0t]

Thank you for the thorough explanation.

[@GreggAndely]

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

[@xxvodanhxx]

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.

[@mofared]

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.

[@6F6G]

If you suspect an electrolytic capacitor has gone high esr just blast it with a hairdryer. If the capacitor is faulty then heating it up will temporarily improve it.

[@carlubambi5541]

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

[@Tommyinoz1971]

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.

[@smartchip]

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,

[@Reuben1024]

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

[@Fourcycle]

I recall reading somewhere that diodes are among the most common low power semiconductor devices to fail. One would think otherwise, it being a very basic semiconductor device, but I've found it to be true.

[@jasejj]

Being the most simple semi, they tend to be the ones that get the most abuse, and run at mains potential etc which a typical IC never gets close to. Failures of diodes in main low-voltage circuits I'd say are rare.

[@SimplyElectronicsOfficial]

11:46 BigClive says "Boom!" Yeah :)

[@billmackinnon6505]

I’m in the position to lay my hands on potentially quite a few faulty 60 watt 4 foot and 2 foot led battens that have failed, most are less than a year old and the electricians rip em out and replace. A quiet word and there now coming my way rather than the skip. Hopefully might get some to work. This is very helpful.

[@billmackinnon6505]

I can forward some drivers if you like. They have quite an interesting wee chip that fails. It may be custom to this driver. Took a fair bit of rooting around to find any info on it. Still waiting for the actual speck sheet from manufacturer. Not sure there will be an equivalent.

[@drsudar]

very useful dissection lesson of the LED driver circuity.

[@simonparker7773]

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 👍

[@andrejrockshox]

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

[@NigelKaz]

Excellent stuff, Clive! Thank you!

[@robbieraychannel]

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...

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

[@arrowstheorem1881]

Impressive electronic skills!

[@hydrusje]

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.

[@jeremyp7293]

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 ?

[@krypton1142]

Hey Clive great video! why would we still get a shock with 0v and 13amps? I thought it couldnt pass through your body if there was 0 voltage. just like how 5v 1A plugs cant give you a shock.

[@bigclivedotcom]

Although referred to as the 0V reference for the circuitry, it's actually referenced to the mains, so a high voltage above ground.

[@nigelkingsley-lewis534]

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.

[@rolanddietrich5776]

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

[@thepussygrabbingfamilyvalu557]

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

[@JamieHamelSmith]

I learned a lot from this one, thanks!

[@wasteoink8376]

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

[@missanna208802]

You sound like you know what's up..maybe you can help me...I've got a plant light that is starting to flicker. The company no longer exists. Mostly it does this the worst when I dim it to 25-50% power on 'pulse' mode, but it will also flicker when I turn up the red beyond about 60%. It has 4 colors I can turn up and down. Red, blue, green, and far red. I assume it is a 3 channel..the red and blue are on separate buttons on the remote, but as you turn one up, the other automatically lowers. These are all adjustable in increments of 5, so if I turn up the red to 60, the blue automatically goes to 40. If I turn up the red to 65, the blue will be at 35. The green and far red, however, go from "low" to 5, to all the way up to 100. I am glad to see that this might just be an issue with the driver, as that can be replaced, whereas a new remote and receiver...there are ones that are similar to mine, but none exactly, and there are a bunch of other features and programs in that controller that aren't in regular RGB controllers like when the LEDs gradually come on and go off at night and at night, after all the other colors go off, the far red only run for about 15 minutes.

[@gooddesign9991]

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.. 🙏

[@MissWobbles]

This guy's brain is set on genius mode

[@fultonius]

Dredging up an old video here Clive, but it seemed like the best place: We've got a Varilight V-Pro LED dimmer in our living room, with 5 Decent LED (dimmable) bulbs in the light fitting. At low levels it's always flickery, but not consistent, more like being over-reactive to slight mains voltage changes. Most of the time it's ok, then you'll just get a momentary drop in light level - quite annoying! Is there anything we could wire in circuit, an inductor / capacitor that would smooth it out? Could you do a tear-down of one of the dimmer switches and a bulb to see what's going on?

[@bigclivedotcom]

There's no consistent compatibility between LED lamps and dimmers. The lamp technology is not easy to use with traditional phase control dimming.

[@fultonius]

@@bigclivedotcom After a bit more digging (aka RTFM) it turns out that the Phillips bulbs prefer the mode 3 "digiflux" which is meant for dimmable CFLs but seems to work better at low loads than mode 1. (both trailing edge)

[@shemp308]

Hi Clive! with this repair it makes me think! I had a little project I was working on a few years ago! But could never find a simple easy to make and duplicate led strobe unit. I know their is a way to do it with a programmer and a chip! but can it be done with simple components? if enough people are interested I would love to see one.

[@bigclivedotcom]

Technically speaking you could make a mains voltage LED strobe by charging a capacitor and using a threshold detector to dump the current in a slightly limited manner through LEDs. Like the traditional xenon strobe. Or just use something like a 555 timer chip to drive LEDs from a low voltage supply.

[@shemp308]

I needed a low volt and did many years ago make a very nice looking us enterprise but I was at the time and later using a 555 timer never able to get anything that looked like a strobe more like a fast blinging! I understand your I would say busy! any ideas would be more then appreciated!

[@RadioJonophone]

I do wish I had written this right at the beginning, but as Clive drew out the diagram, explaining it workings, I immediately thought DIODE. A lot of people become fixated by capacitors, but I've had a lot of weird faults caused by oddly behaved diodes.

[@MusicalBox]

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 KZbin :)

[@chadc437]

I have heard and used the term "bootstrap" a fair amount while in the power generation and heavy equipment industries. I was not aware it was also used in electronics but it makes sense that it is. If anyone is wondering what he meant by " bootstrap" here's a clumsy explanation: When the term bootstrap is used concerning electricity it usually means " to get going initially" if an electrical device is capable of bootstrapping it can get going on its own. Example: Most 1MW+ wind turbines cannot bootstrap as they require an external power source (the grid, battery bank,diesel generator,etc.) to get to the point where they can produce their own power. Internal combustion engine powered generators can bootstrap and are often used to get other forms of power generation equipment up and running.

[@newjerseybill3521]

"Most 1MW+ wind turbines cannot bootstrap as they require an external power source (the grid, battery bank,diesel generator,etc.) to get to the point where they can produce their own power" For the initial field excitation?

[@chadc437]

+ New Jersey Bill Yes , field excitation is a part of it but excitation come quite a bit after start up. Powering the up the controllers, the meteorology and wind sensors,control boards,charging the DC bus, slewing into the wind,etc come before excitation and require an external power source.

[@newjerseybill3521]

Ahh, for all the ancillary equipment.

[@RavenLuni]

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)

[@markdarby75]

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]

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.

[@animarkzero]

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 ;)

[@robbs96]

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

[@SigEpBlue]

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.

[@phils4634]

I was expecting capacitor failures with a few bulges in the larger ones :D

[@Bob3519]

Another great video. Thanks for sharing.

[@ahmedabdallah6157]

Lovely , keep up the good work

[@TheSpotify95]

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]

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.

[@SigEpBlue]

Interesting defect. I paused the vid to look up the FR107 datasheet, and the specs should be adequate: 700 V RMS, 1.0 A If(av), 500 ns max recovery time. It's NRND (not recommended for new designs), but still.... I guess the manufacturer used subpar parts, which would be corroborated by the poor solder joints. Nice detective work!

[@minisareus]

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

[@tommacmillan8831]

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.

[@gordonmcmillan883]

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-)

[@RobertShrimpton]

Nice diagnostics!

[@charlesw318]

great video thanks for the information on the diode.

[@12vgs8606]

One of the LED annular ring light starts blinking after it has been on for a while. The driver does not feel too hot to touch. This is a 36W driver connected to couple of annular LED rings. I just want to know if there could be fault in the LED ring itself or it will always be the driver?

[@bigclivedotcom]

When the LEDs are in series it's not uncommon for the whole string to start flashing when one LED starts to fail. If the fault is allowed to evolve a small black dot may appear in the faulty LED. If it does and the LED is shorted out the rest should light OK.

[@12vgs8606]

My previous experience (with other LED string) had been that one LED used to open up completely instead. After soldering a shorting wire on it, eventually another LED gave up too. You are suggesting that may be one LED is developing open circuit when it gets hot and immediately cools down after opening up and starts flowing again. But the frequency of blinking seems very constant and I also notice that the entire string brightness seems to be less when it starts flashing. If the converter fails to deliver the required voltage at the designed constant current, would it starts flashing?

[@cmj20002]

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.

[@jamierollinson9354]

No user repairable items inside.... I always asune that is a challenge

[@bigclivedotcom]

Exactly. I particularly like it when it says LED lamp cannot be replaced. Challenge accepted!

[@44R0Ndin]

Same here. If it's broken, I can't make it worth any less to me if I try to fix it. The only thing I lose is my free time, and I can potentially gain knowledge and/or a fixed device in the process. The one exception I have to this is electronics potted in silicone rubber, epoxy resin, or bitumen/asphalt. Potting compounds are just a general pain in the butt to try to extract anything from in an intact or repairable condition unless you want to use chemicals to dissolve them, and those chemicals are generally something you don't want to have to deal with if you can avoid it. Additionally, there is a very good reason the electronics were potted in the first place, usually something such as high voltages (ex. CRT TV flyback transformer/voltage multiplier assembly).

[@SigEpBlue]

Such items are always worth putting in the toaster oven for a little while. :)

[@Elfnetdesigns]

I always see the "Danger High Voltage" as a challenge..

[@44R0Ndin]

ElfNet Gaming To be honest the high voltages are a secondary concern. Most of the time I'm not going into potted electronics simply because it's such a pain in the ass to get the dang thing apart in the first place! Mains voltages I will mess with no issue, but I'm going to be using the one-hand rule. That's why I have an alligator clip attachment for the test leads on my meter. It allows me to do voltage checks without needing to use both hands. Charged capacitors get the one hand rule, the "chicken stick" treatment, and placing a jumper lead across the capacitors at the first opportunity so they STAY discharged. Certain kinds of capacitors can actually recharge a little bit after being discharged and that can build up enough charge to bite you rather hard if you're messing with something like capacitors recovered from an AED with an expired inspection cert. A "chicken stick" is a jumper lead with one end attached to a length of insulating material, and should probably include a 470k 10w resistor if only so you don't "hard short" the capacitors (that can do some damage some kinds of capacitors even if it doesn't kill them "right then"). I chose a 10w resistor more for flash-over voltage than for actual power dissipation.