How to troubleshoot and repair LED TV switch mode power supply boards.

[@videobrownsville]

I really appreciate this tutorial. It is better than a school. It is like I am your apprentice. I am an EE and have been to many electronics classes. Your straightforward way of teaching is priceless.

[@bigdog8882]

Glad it was helpful!

[@bigdog8882]

Also make sure to check out my new course, bigdogtvrepaircourse.mykajabi.com/

[@kazdean]

Do yourself a favour and learn from somebody that knows what they are talking about, this guy is a clown

[@mjbalza]

I started learning to repair TVs a few weeks ago, I have seen hours and hours of videos and tutorials but your is precicely what i was looking for, an explanation step by step of every section of the powerboard so we can understand the flow of energy and what can go wrong, this is with no doubt the best Video about TV power Supply troubleshoot. Looking to find the part 2

[@bigdog8882]

Thanks. I also have a really good Course that gets even more detailed on the SMPS. bigdogtvrepaircourse.mykajabi.com/

[@mjbalza]

@@bigdog8882 I have a JVT 50" TV with no standby voltage that I am trying to fix watching your videos lol. It has 12V but no 5V or PS/ON

[@winstonnorville1949]

Thanks for explanation of Power Factor Control circuit: what it does, how it does it, which components it does it with, how to identify those components. That is exact circuit I was struggling with for Sony Aquos 46" TV for weeks now. You have really straightened it out for me. Keep up the good work.

[@bigdog8882]

No problem Winston! U Keep up the good work too, and thanks for watching!

[@larrymclain]

I’ve been teaching myself circuitry for the past 5 years as a hobby and my education in electricity has really helped me out. It’s just understanding exactly what you’re showing is where it’s at. I’m having a little issue with a tv I recently got from market place for free. It’s a Hinsense 75 inch android tv built in 2020. When first powering it up the backlight will flash then darkness. I can use my flashlight and see the picture. But here’s my question.. Why is it when I first turn it on, the backlight will flash but if I unplug the backlight connector from the power board and then plug it back into the power board nothing happens like no flash like it has when it’s first turned on? So what would kill the DC voltage at the backlight connector when the set is on? Any direction u can point me to where to check would be greatly appreciated. Thanks again for the great educational videos!

[@jordanmercier3616]

Thanks big dog, really straightforward, way of teaching, flipping between the witing diagram and the actual components on the board is extremely useful for me. These videos are an invaluable resource for people like me, seriously appreciate it.

[@bigdog8882]

Glad it helped. The course is waaay better.

[@ROOGGGER]

this is quality, hands on explanation, well presented ,easily followed and understandable. thank you

[@yubeme120]

Lol. It's a good thing ypu clarified that board issue, and I love the way you put it on friends and family!!!! Lmao!! Enjoy your feeds. I pick up something every time. Thank you

[@tubeDude48]

Glad to see you do something other than change LEDs!

[@bigdog8882]

Me too, unfortunately LED Video's produce more views, plus its pretty much 90% of the repairs that come in.

[@Gelf54]

Great video. Small correction...NTC - resistance goes down when you heat it, not up. Limits turn-on surge through the bridge rectifier because of the discharged main capacitor.

[@bigdog8882]

You are correct. Thanks!

[@djrenault]

this is a tremendous video. i have watched lots of videos about SMPSs but it's finally clicking thanks to yours

[@bigdog8882]

Make sure to check out the course. Its absolutely amazing. bigdogtvrepaircourse.mykajabi.com/

[@nyambemundopu1168]

Good job Bigdog8882! I like your explanation, you broke it down to component level. I wish you could a lot more of such video where you even draw circuit diagrams. Keep up the good work.

[@vernonbosshard9317]

Thanks for the link, we studied PFC correction in AC, we did labs using inductors and caps, series and parallel, making freg resonant circuits, freq filters, etc, we did all the calculation, wrote lab reports.... I also took AC power and we talked about power line power factor, these circuits weren't in use then, I just need to study them a bit to get up to speed. I found out on my Samsung plasma, the PFC FET was a dead short, actually has two FETS in this one, and hey I saw a video on how to check FETS (remember I asked how to check FETS) I checked the good one, it worked. Good day for sure. Soon as my parts come in I will let you know if the TV works, it should because all the other fuses were ok. I saw another video where they had a shorted PFC FET, they took it out and ran the TV without PFC, seems risky to me. I bought the repair kit from shop jimmy but they don't tell you whats in the kit, WTH is up with that? I kind of need to know right. I bought new NTC therms, (they smoked) two new FETs and the repair kit, about $50 in stuff. And on top of this, a couple solder joints broke loose from just sitting it on a table to work on it.

[@markkalembelembe323]

Powerful lesson on repair of SMPS. Especially on power factor correction. Thanks Guru

[@bigdog8882]

Also make sure to check out my new course, bigdogtvrepaircourse.mykajabi.com/

[@VideoServicesLI]

Thank you for this video, great explanation. That's a nice meter but didn't get to see it in most of the video🥴 That Samsung board is very nicely laid out. Looking forward to part 2 and hopefully some oscilloscope use.

[@abdallahelectronic19]

Thank you, sir, for a good explanation. I am waiting for part 2 if you can support the explanation using the oscilloscope

[@bigdog8882]

Will do, thanks.

[@abdallahelectronic19]

@@bigdog8882 thanks ,we wait

[@Opapa-Jan]

I discovered your KZbin channel today. Wow This video is so well and clearly explained. I will definitely be watching the rest of the videos as well. Very educational.

[@bigdog8882]

Awesome! Thank you!

[@mendiarapi]

Crystal clear explanation. You really took your time for it

[@stephenb4411]

Thanks BigDog, looking forward to part 2, already learnt lots as a newbie. 👍

[@arielmieses8487]

Brother thank you very much for this video, it has taught me so much, I’m still going thru my first right now, I’m not getting 5Vdc to the main board.

[@bigdog8882]

No problem. Make sure to check out the Course. I cover that in detail. bigdogtvrepaircourse.mykajabi.com/

[@Mereda777]

thank you brother ,best tv guy to watch

[@CollenMbewe-ld4jz]

You are a good teacher ,thanks alot

[@waltschannel7465]

Your channel is awesome! I just found it looking for clear explanation of how SMPS works in aTV. I see lots of other TV troubleshooting videos of yours that I now want to watch because You explain things so clearly. There are a lot of smart people doing KZbin videos but most of them talk way too fast and they don't follow up their explanations with actual circuit measurements and give the human brain enough time to process at all. You're doing a great job keep it up!!!!

[@bigdog8882]

Make sure to check out the New course. bigdogtvrepaircourse.mykajabi.com/

[@waltschannel7465]

@BigDog8882 very cool! Thanks!

[@shenlun]

BigDog really loved the video, do you have a beginners guide to this side of electronic repair. I am a newbie to this industry and want to learn the right way.

[@bigdog8882]

No, but U can just google it online. Plenty of books and electronic course's.

[@KassiLyn]

So glad I found your video, thank you so much! You're awesome

[@OGGamer1973]

Love your videos big dog I do electronics too been doing electronics for over 30 years I love what I do too

[@ckimsey77]

Sadly as a chemical engineer im not as adequate as id like at electronics, mainly self studying to ultimately be capable of buiLding custom circuits needed for electrolysis power supplies...but repair is also handy for now to learn. Really loved these vids bro; amazing job at explaining this and showing schematics along with the actual circuit really helps. This is mid-high level concepts yet delivered as beginner level clarity. Definitely subbing to watch more. Just wanted to say you sir are appreciated; thank you for your time

[@bigdog8882]

Thanks for watching Chad. Maybe check out the Course, my students are loving it. May interest you.

[@ckimsey77]

@@bigdog8882 yeah i was looking through your videos on the channel; i thought with you being so knowledgeable in this area that you might have videos geared more toward teaching the concepts of how it works rather than just repair. Theyre really helpful, ive watched a couple and plan on watching more as i get time

[@bigdog8882]

@@ckimsey77 Yeah that whats in the "The Art" course. Its Amazing according to my students. bigdogtvrepaircourse.mykajabi.com/

[@sneakyquiet414]

Finally been waiting on this course been scratch my head on ps repair thx for this video waiting on pt 2

[@ngeksinoto5950]

I'm newest subscriber here love that hobby too keep it up from philippines

[@Dreyden-]

Thanks for these vids they are awesome to watch

[@cat-lw6kq]

Thanks Big Dog I've been pulling boards from broken sets a d trying to fix them.

[@jkar6744]

Excellent tutorial, love the way you explain things.

[@dzabakwesi2213]

Thanks for the video and the knowledge.

[@computerguy7213]

really great video, although your definition of the fuse was wrong. The fuse is to protect the power supply from internal malfunctions, not for for the incoming voltage. A fuse has two ratings, a voltage and amperage. the amps of course is what the max amps that the fuse will open and the voltage is the max voltage before the voltage arcs across the fuse. most fuses are rating at 250 voltls, so for a 3 amp fuse it would be 250v 3amps. so what that is saying is over 3amps the fuse will open and over 250 volts there will be an arc over from one end of the fuse to the other whether or not the fuse is open or not

[@johnparker9482]

Outstanding information Big 🐕

[@jeremygardner1981]

Awesome video, can't wait for part 2. Also a need info on backlight inverter circuit. Subscribed!!! Thanks.

[@bobbertolino8474]

Just discovered your videos-you do a great job explaining circuitry-much respect for your efforts! Just one thing I noticed from a safety standpoint..your tendency is to lean your chest across the PS board when plugging in/ unplugging power cord. You may want to relocate the power supply/cord closer so you dont have to lean so far. Otherwise, excellent work!

[@bigdog8882]

I already past the shock test 50+ times, lol. Thanks for the advise. Blessings..

[@bokaboi]

Hey mate. Thank you for taking the time to make this great video. I’ve learned a lot. I have Sony Bravia XR-65X90K. You had said that Based on the instructions in this video I was able to check the fuse, and was able to get 3.5VDC of standby voltage. I have replaced the mainboard, but it’s still dead. Would you suggest I look at replacing the T Con, or the board that sits between the main board and the power supply?

[@bigdog8882]

Hard to say without Troubleshooting the TV. Sorry!

[@josemariaramos68]

Master thanks you for tutorial

[@chisum0]

Hello, enjoy your videos and they are very informative. Except for I have one question. I have a Samsung 48 in no smart TV that seems to have all the power but no picture. LED lights come on, and so does the light for the power switch. Check all voltages they are as to what they're supposed to be. Please advise.

[@bigdog8882]

If you have backlight but no image, check t-con and/or panel.

[@TheWolfster001]

I have a question for you.. Can you replace the factory led backlights, with led strip lights to make the tv even brighter.. My thought is it can make a TV bright enough to actually watch TV outside without having to place it in the shade.. This also could be a build you can do, just to test and see if it would work.. It could be an awesome video too.. Just asking.. Also. I love your channel, a couple things at times goes above my knowledge, Still I find them all very educational and very entertaining...

[@jonsnell4751]

PFC is Power Factor Correction, not Pin Cushion!

[@larrybland007]

Thank you very much

[@SouthFlorida4DoingLife]

Hey Big Dog, I love all your videos and take great knowledge from all of them, got a question for you on a Samsung when turning it on it flickers and continues to flicker. There was one time that it came on and worked fine until I turned it off. Now with everything unplugged except the back lights plugged in it is now doing the same thing all over again. When probing the board I find my standby and all of the powers that go out to the main board to be DC voltage going up and down up and down fluctuating bad, I visually inspected all the capacitors and solder joints to my knowledge they all seem to look good. I was wondering which component that I should redirect my attention to on this board. I got a Samsung BN44-00708K, as you have said in your video Even though the capacitors may not look bad they could still be bad so I'm going to go back and check like you said on the primary side before that transformer to see if there's any faulty readings while having the power supply plug in and that's it. Thanks for all your help big dog, and hope talk to you soon. Oh and one more thing while having the power supply powered up and the back lights plug in and doing the flickering thing, as soon as I plug the strap going into the main board I hear a a squealing sound coming from one of the components off and on until I unplugged the main board again. I'm pretty sure it's got to be the power supply board but any info you have I will take.

[@fajile5109]

Ok i was confused because when i looked for examples they always have a transformer in there but this takes ac from the wall and converts it? I wonder it thats more efficient for continuous running?

[@bigdog8882]

I think your referring to a Linear Power Supply, Switch-Mode Power Supplies are definitely waay more efficient. I cover that in "The ART". You would definitely understand why and how its more efficient in the first couple lessons.

[@blakewilliams6613]

good video

[@josepeixoto3384]

on this LG lcd tv, i do have the 3.5 V but the set will not turn on; the pilot light is on; there is no 12V and no 24V; it draws 220AC current for 2 seconds ( my test series 60 watt bulb lights up,then goes to nothing) thehorts anywhere in then nothing; no shorts anywhere in the board, is it the PS or the Main Board? (the pilot light stays on,but after pressing Power On, it stays blinking slowly)

[@kazdean]

Go back to school, the RC filtering on the mains is not to provide "cleaner AC to be rectified" it is to stop RFI getting back on to the mains. Also the thing you call a "rectifier diode" is actually a bridge rectifier. The PFC circuit is not for boosting voltage, its job is to bring current and voltage into phase to boost efficiency. the NTC thermistor resistance goes down when it get warmer not up like you say. It's job is to limit inrush current at power on, it drops in resistance as it warms up to improve efficiency. I cant watch any more it is too painful. I recommend anyone watching this to learn go elsewhere and learn from somebody that knows.

[@dzabakwesi2213]

Please how do I overcome the fear of troubleshooting and measuring the voltages of components on power supply board when connected to AC source because I always fear blowing up any component on the board especially drivers ? Or what is the better way to troubleshoot power supply( is it when connected to power or not). Thanks

[@bigdog8882]

Use an isolation transformer.

[@dzabakwesi2213]

@@bigdog8882 please thanks for the response. But please can you clarify what you means by isolation transformer because am a beginner thanks.

[@bigdog8882]

@@dzabakwesi2213 just go to ebay, google, amazon etc. Just type in "isolation transformer". You plug the device your working on into the isolation transformer. It separates the device from the main socket's hot side, giving less risk of damage in case you short something or make a mistake.

[@dzabakwesi2213]

@@bigdog8882 thank you very much sir for the response I really appreciate.

[@blingmotions6996]

Morning sir I would love if you could help me solve an issue with a toshiba led tv 40" model 40L1400U it has know standby light no power on the wires going to the motherboard even with the backlight disconnected...

[@kevinpaugh1803]

Hey Bigdog another great video on power supplies troubleshooting. I have a LED Samsung UN60JS7000FXZA version (MD01). When I unplug the main board from my power supply, the backlights stay on for a few seconds and then turn off. I would expect them to stay on continuously. When I try powering the set with everything connected it flashes the standby light 5 times and never comes up and backlight never lights up at all. I do have audio from the speakers. Good news is that my standby light does come on. My Standby power test point seems to be ok (8 and 13V) and LED output from the board is around 300VDC with no load. Do you think I have a bad power supply board since the backlights do not stay on continuously when disconnected from the main board? Could the blacklights pull too much current or be possibly shorted to ground causing an over current condition? What do you suggest to troubleshoot at this point? Thanks for your help!

[@rodwillett8814]

Awesome video. Have you ever consider doing a live zoom class? I would pay five bucks for one hour. You could make a little money on the side. It would give us a chance to ask questions.

[@bigdog8882]

Good Idea.

[@charliewhite7596]

Power light on tv comes on then slowly goes out. No audio or picture. What would look for first. Every one i call for complete boards say out of stock

[@hansmagielse645]

Question , i have a lg43uk6470plc tv and the main board was bad , i replaced it with a board with matching EAX and type but the flatcables on the New board are smaller , do i just need New cables or do i have an incorrect mainboard ??

[@bigdog8882]

Most likely an Incorrect mainboard. Use the EBT...# on the white/orange sticker.

[@akmalfiroz6732]

I have recently purchased a dvd player but it has a problem that when I put a disc it loads perfectly and when picture should come it restarts and sometimes it loads perfectly and play the disc from beggining and when I change the track like when I select 5 or 6 number from remote it restarts again please reply

[@bigdog8882]

first thing I would do is clean the Mode Switch.

[@shahidchattha2553]

I am here in North Carolina, need more help in tv repairs. How can I get in touch with you.

[@bigdog8882]

Make sure to check out My new Course, bigdogtvrepaircourse.mykajabi.com/

[@shahidchattha2553]

Hi bigdog, I repair TVs for living but sometimes I can not repair boards. I need to contact you for power board repairs. I want to send you my boards for repairs. Please let me know how can I contact you directly for future business. Thanks.

[@bigdog8882]

bigdogelectronics.us/

[@GoalSideCalcio]

Could you help me I got a black screen 32in jsw smart TV it shows no picture but back light an sound an wifi works.......I never drop it it just faded to black

[@bigdog8882]

If u have backlight but no video image, then check T-Con board, or bad lcd panel.

[@GoalSideCalcio]

@@bigdog8882 so the tv isn't responding to instructions from the remote it's a brand new remote an batteries so could that confirm the bad t-con board?

[@MtPockets14U]

what meter are you using?

[@bigdog8882]

bigdogelectronics.us/products/dt-9989-professional-digital-multimeter-oscilloscope-lcd-color-screen-usb-current-voltage-test-electrician-tools?_pos=9&_sid=1f880036d&_ss=r

[@bigdog8882]

*Hey Guys, My NEW Television Repair COURSE* is now Available before Launch date. MORE INFO>>> bigdogtvrepaircourse.mykajabi.com/

[@MrFelatio1]

okay

[@jamesramsey1094]

I'm not as knowledgeable as you would it be possible to help me with a plx3002 amp I'm working on its not turning on I'm in the Philippines and its almost impossible to get information here ty

[@bigdog8882]

Google It.

[@jamesramsey1094]

@@bigdog8882 Google is philippines based here i tried it don't work

[@johnkosick1464]

You didn't show the mutimeter readings from the 13minute mark to the 22min. mark. If we can't see the meter, its not very informative. I was looking forward to a very good video on this power supply board, but it was disappointing. Evidently, most of these other posts don't know how to make a good presentation about electronics......... @ its called "Constructive Criticism"...FWIW.

[@techstuffhere3158]

Hey My board's Mov is short and there is no Ac supply at bridge rectifier at secondary side plz suggest what should I do Thanks