You started out with a SMPS made by Power Systems, Inc. I was the Product Safety Engineer for PSI for nearly 30 Years. I think the model shown was in the series of late PS-1600's or PS-1700's. Enjoyed watching that work again! LOVED that company and my old job! I traveled all over the world for them. BTW; that green module in the primary has a saw tooth generator and a low voltage dc reference voltage that slides up and down across the saw tooth. thereby tell the switcher to stay on for a longer or shorter period of time based on the load conditions, as felt thru the feedback loop from the sec to primary using that opto you spoke about. Wow, I am retired and its been over 10 yrs since I left America. (retired in Philippines) PSI went out of business about 8 years before that! So, the memories are wonderful! Also, the reason we used the RTV between all the caps was to add ruggedness to the supply. We used a HALT test chamber and a random vibration test at the same time we took temps up and down to find the failure points. We brought them up to about 140C before they failed, then down to -60C before they failed and found that most of our supplies lived at 30G's but would fail by 60G's. I ran that area. My people monitored about 30-50 components during the test for temperature and we monitored the input and output voltages on each channel. I also ran the RFI/EMI Testing and got them approved thru UL/CSA/TUV, etc. (I believe the standards that one met was UL/CSA60950) and often made sure they would pass the conducted and radiated emissions testing also to ISO Standards. I also sat on two technical committees in Canada helping to write the International Safety Standards for the IT industry. Later, I worked for the German TUV Agency as a Product Test Engineer. LOVED my work!

It’s just amazing how knowledgeable and unflappable you are, I don’t think there is anything you would not be able to design or repair. Respect

Your shop brings back memories of my father's shop when I was a little boy. My father was an sound engineer for the RCA corporation. Repairing sound systems all across NYC it was great fun being in the projector booths and seeing racks of AMPS in the winter you never needed heat the equipment provided it. My dad passed away just as the transistor came on the market every thing was tube operated. I miss his great wealth of know how from radio and tv repair which I saw from a very young age. He started his repair business in 1918 when he was 14 in his fathers basement. I became an electrical contractor installing alarm systems and generators building my own controls as much was not commercially available. Customers learned very quickly never say to me it can't be done I always proved them wrong. Much to there dismay and amazement. Today every one in my field is an expert or certified my father would have called them tube pullers putting wheels on miscarriages. Artificial stupidity is what I am waiting for.

Always inspiring to see a state-of-the-art repair methods and decisions. thanks Paul!

If I haven't said this before I'll say it again.. you are a quality teacher. Some people honestly don't have the ability to teach no matter how much training they receive but you have the natural ability. Please keep up the good work!

Absolutely the finest teaching around. You have a gift, I wish my instructors would have had even 50 percent of your ability to transfer knowledge in such seamless way. Best on youtube for sure. Thank You!

One more important comment, to regulate the output voltage, the control circuit senses the output current and increases the conduction time of the switching transistor to regulate the voltage. Love your work!!

Watching these SMPS videos reminds me of my time working at a power supply manufacturers. Testing units from the production line to working with design engineers building their prototypes and developing them to production status. One challenging job I had was developing a 30kV pulse supply to be used on a magnetron. I wasn't privileged enough to know what the final product was (secret stuff). Another excellent video Mr C. and I've watched quite a few of them so far.

I love this. I was an engineer in the UK repairing Hammond Organs for many years. Retired now, but still repair things just for fun.

Best electronics teaching channel I found hands down. I've been repairing electronic devices nearly 40 years full time and there is always something new to learn!! Thank you. 😉

This guy's lab it unbelievable. He does a GREAT job explaining things. Like switch mode power supplies. I watch his videos all the time. Thanks for taking the time to be so descriptive.

The best explanation on how SMPS works with an in-depth explanation of where these are unsuitable and/or what additional devices are needed for these when running sensitive audiovisual equipment.

Scope rebuild? Yes, please! I'd love to see you (re-)building a scope, especially if it's a Tek.

This is the best tutorial about SMPS on utube..thumbs up indeed.

Excellent video. I'm just getting back into analog electronics after a couple of decades focused on digital and programming and find these videos both an excellent learning tool and refresher. Thanks for doing these.

Brilliant. Not that I'm too interested in electronics, but your talent and the way you can talk about complex things in a simple way, I just love.

Excellent video as always. Thanks for your time making it, which I'm sure will be appreciated by lots of viewers.

As usual the best teacher on KZfaq, thank you.

At last! a direct and easy explanatory tutorial on electronics. A natural purveyor of useful information.

Just keep coming back to your channel. Informative and I like the longer videos. I understand how much effort goes into your channel.

Very good explanation of the switch mode power supply, especially with your diagram you drew. If not already, you would make an excellent electronics professor. You have a very good teaching method.

Absolutely fascinating; the world of electronics and the way YOU present it to us. You are an inspiration at best. Thank you so much. I feel pepped up and positive. Good luck and much love. Cheers! 😊👍

Really enjoyed this video. I learned a lot about the difference between the types of power supplies, soldering and desoldering, testing the circuit, and general tips and techniques.

Since as far as I can remember, not sure if I was 6 years or 8, I was always fascinated with electronics (and still am) and wish I had met a guru like you to answer my inquisitive questions on electronics. Just watched your video and got several of my questions answered. Just subscribed as I don't want to lose this channel of information. Your workshop looks like heaven to me. Keep up the great work!

The theory part showing the switching vs linear supply was excellent! I get the feeling a 10x more difficult repair would still be nothing for you.

Thanks for another great video Paul! You're a spectacular teacher. Greetings from Arizona.

Carlson, you are really a good teacher! I learnt lot of electronics theory and trouble shooting skill from your video. Your speaking was so clear and very understandable, even to me a non-English speaker. Thank you very much!

I'm glad we have a great teacher like you. Get the young people of the drugs and alcohol turned on to you. Make America great again. Thank you 🎙

Ah the good ole SMPS the most common failure in modern junk! I spend hours working out faults on that kind of crap. Televisions are notorious for SMPS failures, crusty caps and short circuit diodes being the most common failures, but they can go right down to the darn right obscure and hard to find component failures that make you question the real meaning of life! (But hey, you get a warm feeling when you find the fault or touch the 400v LOL). Keep up the good work, good clear explanations and gripping videos. 5*

Excellent video as always, great information and you make it easy to understand.

after a million videos.... i finally found the proper functionality of the components.. thank you Mr. Carlson.

You ar e the best teacher i ever had. Best elektronic Chanel in KZfaq

Paul, great video! I've been servicing SW mode PSs for many years and have found anomalies that don't make any sense and today was one of those days. Working for a college that has very limited budgets, I have taken it upon myself to repair as many electronic items as possible. The majority of these failed devices are due to a bad SW PS. With a few exceptions, all they needed were new electrolytic caps, and most of the time it is a small 10µf to 47µf cap near the control/regulator chip that needs to be replaced, although, I usually also replace the filter caps at the output for good measure. Anyway, the sole purpose of that small cap seems to be one of obsolescence, or a timer cap. When it starts to lose its capacitance, the output amperage starts to drop and when enough capacitance is lost, the PS may make a ticking noise due to the PS starting and stopping on a continual basis, even with no load. Now for the weird part... I pulled the "timer" cap from this no-name PS (20V @ 2A) since it was "ticking" on and off at about 2 Hz, and my cap tester showed it was well within tolerance of the 47µf value. Normally, this B&K, model 830, cap meter has always showed a greatly diminished value but not this time. I replaced the cap anyway and the PS came back up to full voltage and power output. I then analyzed the bad cap using a sensitive analog VOM and both the old and the new cap exhibited the same readings for charging time and leakage, so I'm at a complete loss as to why the PS circuit likes the new cap but not the old one. And this is not the first time this has happened. The only possibility I can think of is that breakdown is occurring in the cap, such as its leakage is exceedingly high at its rated voltage and causing a shut down. So I put the bad cap on my lab PS and set it to 20 V, and the leakage current reading is 0.2 µA. Then ran the same test with a new cap and it had a current leakage of 1.0 µA, five times higher than the old cap. So, if the leakage current goes to low, these PS's shut down? Could this get any weirder? If you have any insight or info about this anomaly I'd appreciate hearing from you. Thank you.

"Tittally""...I haven't heard that one before :) You mention the one of the greatest tips that I figured out years ago for component removal/replacement...apply fresh solder to any joint to facilitate easy and much quicker part removal, hence, less heat to a possibly fragile board. Also, on an IC that I'm removing and not going to reuse, I recommend snipping the legs off of the body of the IC and then removing the legs one by one. Once they're out, use a small stick-pin and apply the solder tip to the hole to melt the solder and push the stick-pin through the hole to clean it. This process saves a lot of solder wick and/or solder-sucking on most repairs and saves the consumables for the most difficult situations that need those tools. Cheers Paul, Dan G.

This is the best explanation I have seen of a SMPS.Thank you

Thank you for the great video. I’ve watched all of your videos so many times I lost count. Always wonderful teaching techniques… And it keeps me company in an empty shop 16 hours a day. Regarding the pins which you removed from the smaller board. (The ones which damage the copper traces upon removal).... I see that on 50% of the industrial automation and furnace type boards that I repair. Sometimes they are pins like in your video… But usually they are spade connectors or other terminals/connectors. Many times… Especially on mass produced industrial boards… they have been press-fit tight, or fit then flared on the bottom of the circuitboard in a way that makes them almost impossible to remove without risking damage to Traces. I deal with this in two different ways. And this is just my experience and I’m nowhere near as qualified as you. But It’s worked for me and saved a lot of time. Considering I do several hundred boards per year… In a constant heavy flow… i Had to figure out a more efficient way. And constantly having to repair traces is a big downer. First I try and remove ALL THE SOLDER. Which just isn’t possible with a solder vacuum or soldering wick. They get 90%… But it’s that last 10% that’s a real pain. BY FAR the quickest end best method for removing 99% of the solder is by using compressed air (there’s always going to be an atom thin coding left) I like 35 psi, 50 MAX!! Because any more can actually blow the traces off the board!!! I specially customized an extremely light weight “pistol grip style” air gun. The tip uses a basketball inflating needle instead of the standard nozzle. This gives me much better control and forces the air into a little tiny precise stream. still only running 35 psi… But instead of that being spread out over several inches… It’s directed into one little pinpoint. It’s Hooked to a flexible and lightweight airbrush hose instead of a regular heavy compressor hose. It weighs almost nothing, (about as much as a soldering iron including the weight of the airbrush hose.) are use it several hours per day and I was beginning to have wrist trouble so I use the flexible lightweight hose and the plastic body blow gun with a properly angled nozzle… And my wrist feels much better now. So I heat up the solder and then one quick blast with the compressed air… it removes much more solder than a pump and allows me to see the junction of the contact easier. Since it’s easier to view I can usually bend and compress the contact pin or connector until it’s un-flared and small enough to fit through the hole without tearing the traces. Usually they just fall out. And it’s so fast… Because I only apply heat for a half a second... compared to two or three seconds with a solder vacuum.Therefore I am much less likely to damage the traces and loosen them from the board. I can desolder a 16 pin IC chip in under 10 seconds. I can be sold or PC be mounted transformers instantly… Even the ones that have a dozen + thick heavy gauge wires poking through. The air jet from the needle always gets 99% of the solder out of the through hole… Leaving completely loose and floppy leads. Not stuck to the side wall like with a sucker or wick. I Can easily depopulate a entire board that size in just a few minutes....using nothing more than a cheap 40w iron and the compressed air technique. Components simply fall out. I use a cheaper iron for this because constantly desoldering and being blown with compressed air can shorten the tip life. So it’s a perfect job for the cheap $5 eBay knock off T12 irons, And cheap tips. Of course this isn’t ideal because it creates solder splatters that go in all directions. So I lay the board flat in a shoebox so that the box collects the soldier and it doesn’t go all over my shop. But this still leaves the issue of tiny solder specs on the pcb possibly shorting out contacts on the board. Luckily 90% of the boards I work with are conformally coated or have some form of protection on the rear traces. Therefore I’m very careful not to have any solder specs reach the front of the board, But they don’t pass through the hole like you would think… They actually blow out the rear of the board and go in all directions. But I inspect everything extremely carefully and clean very well with compressed air, alcohol, and a wide range of customized paint brushes that can reach into hard to get areas instantaneously. Coupled with compressed air and pure% alcohol… It’s incredible how many things can be repaired quickly this way. The second way I deal with pins, contacts, and connectors… Instead of removing them and risking damage to the traces… I simply add a piece of copper wire up through the hole and to the body of the connector. Soldering it in place. As long as it’s mechanically stable… It usually works and keeps me from having to replace connectors. I wrote an entire article about my custom cleaning brushes and air tools. (no wonder the ladies love me) But I won’t bore you with that here… Over 15 years of restoring vintage machine tools, antique woodworking handtools and equipment, and all other sorts of difficult to clean objects… Finally came up with my own method of customizing a wide range of brushes and cleaning tools. Complex objects like pcb’s can be made spotless in only a few seconds with nothing more than liberal squirts of pure alcohol, and the right size and stiffness brushes for the job… With compressed air… literally factory fresh clean in a matter of seconds. This is just my experience and I’m sorry to ramble on. I’m a nerd when it comes to this crap. Love your videos as always.

Great video can't wait to see the oscilloscope repair :-)

Well explained, I was impressed with the way he removed the ic, and it's so nice to hear him say soldering and not soddering! That drives me mad.

To Mr. Carlson, another great instructional video. I took some electronics class's years ago but forgot a lot of it over the years but the way that you explain things makes even complicated things look less complicated. Thanks for doing a great job helping people to understand electronics. Cheers!

Thank you Sir again! it is my first day enjoying your electronic videos they are really useful, it is hard for me to get out of my computer because I am really learning a lot from you. Thank God that gave you that intelligent and that understanding of the energy that He created.

Man, you are the Legend. I've learned a lot. Thanks

I never get tired of that shot in the beginning. It looks like you're in a rocket ship or space shuttle.

Excellent switch mode PSU description. It really filled in the limited knowledge that I previously had. Especially regarding the safety requirements with the AC line voltage. Thank You!!!

Thanks so much for a well scripted film.If it's not scripted,you have an incredible sense of what to show us.I'm working on a Behringer PMP1680s Europower powered mixer that just blinks the leds on the front panel.I'll now be able to check some of the SMPS, key components. Thanks again!

If I need to replace a through-hole IC, my preferred method is to cut the pins as close to the IC body as possible in order to leave as much of each individual pin in the board as I can, then I simply go round and remove the remains of each pin with tweezers and my iron. Then remove the solder with wick. Using this method lessens the chances of damaging the PCB significantly, it's also a lot easier and faster.

Hi Paul, great explanation and rebuild / refurbishment of the SMPS. The mystic falls around SMPS technique :^) Take care 73

excellent n fruitfull video for those who r interested in SMPS power supply.Good that u have shown the importance of SMPS over linear power supply.thanks for video.

Totally a nice video with specific reference to the leaky capacitors replacements the care need to be exercised. Thank you Sir and hope that more like this might be posted in the days ahead.

When replacing polarized parts which are not marked (I.E. caps), the easiest way to identify the negative is to put your meter on continuity and put one probe on (chassis) ground and the other on each pin of where the cap goes until you get a beep.

It would be an interesting challenge to reassemble the oscilloscope and could be a fun video!

Best tutor in the world,You would Love Electronics after Bad things Happen..........Thumps up for this guy!Now thinking on building a Power Supply that turns the whole world on!!!!!

THIS GUY SURE UNDERSTANDS HIS WORK AND MAKES IT EASY FOR A BEGINNER IN REPAIRS UNDERSTAND

"Bad things happen.. Really bad things" cracked me up lol. Nothing wrong with some magic smoke if done on purpose. ;)

nice work Mr C. thanks

Awesome video. I'd like to see whole series with more details. Good job.

This clip took me down memory lane and my working with a Ikegami monitor with a SMPS; it's a dog chasing it's tail. Just starting my career as a post production engineer and during the interview of my soon to be employer, my future boss handed me a circuit board and asked me what it was. It was a SMPS. He then wanted a description of it. I pointed out everything on the primary, secondary ....etc. His jaw dropped and the next thing out of his mouth was ..."the job pays ......."

Mr Carelson...did you Test the IC's after Removal? Did you Test the Removed Capacitors? Would like to know what Component/s was causing the Unit not Operate.

When removing a sus IC just cut it out from the top. Less heat stress on the copper tracks.

Another great video. Loved the beginning with the overview of the different regulator circuits.

Always enjoy your “speciality” work. I’ve got a cheap switcher that’s dead and I look forward to attacking mine. I wanted a cheap high current 12volt PSU but it died a whimpering death. Always enjoy your programs to glean all I can to get back to getting my vintage equipment back to use Thank you as always and Happy Thanksgiving, Merry Christmas and hope we both have great 2024! Bill Martin, KA1TIU

my brain after watching this: " *I Know Kung Fu* "

Again, A+..................

Many thanks for your excellent tutorial. I was a TV technician 50 years ago, repairing tvs to component level. Then I moved up to Avionics tech job and later on to an aircraft engineer's job. I retired after 40 years without board level repairs. After retirement I find a pensioner's life extremely hard. I am refreshing my electronics knowledge to be able to repair TVs or Computers.Please keep up the good work. aftab ahmed. London

Paul another great video. I have really enjoyed your videos and have learned a lot from them. Keep them coming. Tony

When replacing ic's always put a socket there.

How the "F" can anyone dislike this video?

Always very interesting to watch and very informative. I've been in power electronics all my life but you always teach me something!

Outstanding once again. You are absolutely the best tech and teacher I have ever encountered.

WHAT! Single puny diode rectifier on the output? You need a FUUUULLL BRIDDGEEE RECTIFIEEER for high power applications. Mehdi will be mad!

Thanks for the tutorial vids. Your explanations are easy to understand.

Best explanation I've ever seen.

Excellent video! Well explained, good audio, good vision. Thanks.

Amazing video! You are great teacher, knows the topic, explain with detail and easy

Great demonstration Paul; switch mode supply are very efficient, the only downside is they need about 90 volts to start making variable increase very tricky and in some cases blow the power supply when it pulls to much current. As I recall the switch mode operates within +-1% making regulation very tight.

Finally got around to checking this video out since the p.s. in my Tek TDS460 is the same and found the caps good, but what appears to be quite a few solder joints on the output pins looking dry. Pulled the caps and all mine tested good with no physical leakage. Thanks for the video!

Thank you for pointing out how noisy the switch mode power supply is. As an amateur radio operator I have heard what happens when a radio uses one of those supplies.

Very nice! With love from Romania! Esti un învățător desăvârșit!

Bravo Paul. Thank you very much for sharing these awesome videos with us. I do appreciate the time and effort you put in to each and everyone. All my best. Bobby

Thank You, again, Mr. Carlson. You are one of the few best! Maybe tied for 1st, IMHO. I am sure many would agree.

I sure like to know where a person can buy that desoldering iron you are using. And I love your positive disposition and the added simplicity is just more icing on the cake.

2 yer old video, but still a great watch. Fantastic explanation of everything you did and saw.

Almost 10 years ago, I repaired one of these supplys that wouldnt turn on. In the process, I shorted something and blew up the switching transistor and the hybrid. I ended up doing exactly as you said. I scraped the green stuff off the hybrid and replaced the damaged components. That was a real pain in the butt! Turned out that the no start condition was from a bad cap under the heat sink. The smallest one on the board. Love your channel!

Yes , i do learn a lot from this teaching .Thank you Mr. Carlton for this video

Your welcome. I won't miss any of your videos. There is good repairmen and there are great repairmen. You are great!

Hi Paul, MCL, Excellent tutorial on Linear and SMPS supplies. Good job on the fix. MCL is a goto channel that delivers credible, accurate, and, depending on the subject matter, easy to understand information, when your a newbie, it makes a difference. Thankyou. Take care, C.

Great video, as always, Looking forward to the "scope build" . Thanks, Greg

I learned a lot about switch board power supplies for your video. (I'm attempting to repair a power supply for an ASIC bitcoin mining machine.). Extremely helpful! Thanks!

Amazingly awsome simple description of a smps. Ty.

Fantastically informative - I learnt masses - thank you very much for taking the time to make it.

Excellent instructional videos, sir. Thanks for sharing your knowledge. I think I can now attempt to fix the power supply in my Cisco 500 series POE switch. Greatly appreciate your time.

Man, I love this channel. Thanks for showing your technique for removing I.C.'s. They have proved to be a real pain for me in the past. Excellent stuff. Now, where is that old CB power supply I have that does not work?

Tnx sir, you shared a very helpful and informative knowledge especially to us who repairs smps powersupply. This very helpful to me sir as electronics technician. Tnx sir for sharing knowledge sir🙂

Electronics - it calms even when watching someone else's fixing it. Thx Mr Carlson!

Great video. I love the repair and troubleshooting videos. Thank you for all your great work.

no other great technicians exist on YT !!! but I do think that Guy from down under, in OZ, you know the one is another great star. You two should get together and do a marathon ultimate diagnosis repair, restoration project.

I realy enjoy the presentation. This is the exact amount of information what is needed here.

Great video on repairing switching mode power supply

Paul, Another fine video. I'm working on bringing back into service a Yaesu FT-901DM transceiver that has not been used in 25 years. It does power up and receiver is OK. The plate current and PO meter gives no readings, however there is output into the dummy load. Just started working on the project and hope there in nothing too seriously wrong. The radio gave me many hours of good service.

Commenting to watch this later. Working on some power supplies as a student for UMN smallsat. We have a power supply for some external testing that we bought which is of the switching variety. Edit: Man this video is fantastic.