Tv repair - switching power supply TL431 feedback circuit

[@destination-nn1zq]

I think Sorin is the best teacher out of all the online tutorials ive seen and what i love best about his videos they are a wharts and all live video......where occasionally Sorin is left baffled by certain electronic behaviours and shows that as skillful as he is he doesn't always have the answers and that's ok because in every single tutorial of his ive seen i always get something out of them...... Please keep making your tutorial videos you are an inspiration to so many electronics students around the world thankyou so much

[@Jan3Sobieski5]

17:57 your coworker is really jamming to some crazy beats ;)

[@virusoiul]

m.kzbin.info/www/bejne/ioq7ealvbNCVptU&start_radio=1 to be more precise

[@LeonardodeJesusMiron]

hahahahahaa

[@OFDM-network]

Its actually around 60VAC

[@Struktualnyj]

This video wasn't pointless - it was real live. Thank you!

[@medicfour9268]

It's great to see you back Sorin!! Hope all is well with you and the family. 💖 Just remember that what is "boring jobs" to You is interesting to us, well to Me anyway, Digitizer replacements, screen replacement videos etc are worth making and uploading. I will watch every one of them. Anyone else agree? Comment here so he knows.

[@peterhodgkins6985]

It's amazing that you can swap out those tiny components so quickly and easily... The intermittent problems are the real difficult ones to find! Love the videos!

[@kamelt3574]

The best "Hello!" on the web. I am no electronic guy, but used one of your vids to fix my laptop, since, I viewed some of your content, read the comments and completely understand the appreciations of the more techy viewers. Respect.

[@mohammedsalhi591]

thank u so much sorin. you are right it s very common problem but you are the furst to explain it clearly. thumbs up!!!

[@61spindrift]

Did you say "pointless"? Like this video was not helpful to all that watched? You could not be so wrong. It was GREAT! When most techs would only show problems with a definitive fix, you show us what could happen to us DIYers. And that is that you could work on a problem and all of a sudden it just starts working again with no reason why. I and probably others on here thank you for showing us everything...the good and the bad.

[@vincepirozzi9603]

Thank you, thank you! I am working on a DVD player that is dead because the switching power supply is not working. I know the problem is that the switching pulse is not getting to the Midgets but can't figure out why. Everything on the board seems to be OK. Then I am watching this video and I notice that the schematic you are using is very similar to the one in my power supply, including the opti-swtich and the keying diode. I ran the test as you did with an external power supply and it looks the opti-switch is not flipping like in your circuit. I would not have thought of that without seeing your video. I ordered a new keying diode and am pretty sure that should fix it. Thanks again for the great tip. Vince

[@daz41262010]

great work Soring :) even the TV gave in to your superior repairs :)

[@mohammedhassanademadem]

Thank you Sorin. Stay blessed man 🎊😼🥀🌷

[@Radek__]

9:02 Sorin you forgot, that if the board is not working, but after put it back is working - then it has to means: cold joints OR ground screws was not screwed thight. Just look at theese 3 cracks on the solder joints at 9:02 :) You missed them - TV will comeback again :)

[@hightttech]

SORIN, thank you for uploading video. Demonstrating FB ckt very helpful for future. I hate when DUT mysteriously begins to function during handling / troubleshooting. Cheers

[@enriqueaguilar964]

maestro buenos dias desde Mexico!!!

[@transformateur9969]

A thousand thanks for this beautiful instructive video

[@atoms1978]

It really brightens my day.

[@geraldfactor5781]

some times there is a magic in electronics

[@ecobob101]

lol funny - still enjoyed the it - also learned about that chip. I have had two possible issues similar that it could have been that chip... as I was stumped. Also I use to check to see if there was resistance or no resistance on the opto when it was plugged in so this way will make me feel a bit more safe and give more info - thanks

[@1657joker]

So good Sorin .. thank you so much 😃😃

[@juarezcastelo]

In Mexico, when it looks like a device repaired itself, technicians say: "It was afraid of me"

[@OFDM-network]

Are the diodes at the output the schottky diodes? Whats the part replaced around 10:00 part?

[@ndttv8682]

I realy like ur video sir Im from phillipines ... mindanao

[@ismailyuksel3459]

Thanks nice video solve problem smps

[@Humilityismyaim]

I have to assume there was a flaw in the soldering job for that chip. So your re-soldering it fixed it. No apologies necessary

[@MatiusLenin]

Perhaps the heat revived the component.

[@paolomonai9511]

@@MatiusLenin The culprit perhaps is a cold joint....

[@wisher21uk]

Crap vestel boards could be intermittent backlights sometimes heat can bring things back to life but soon fail again, It will be back you have my word lol

[@zx8401ztv]

The power supply was blowing raspburys at you lol, i've had that happen with other devices. The TL431 is a precision shunt regulator that can be programmed with two resistors. It's input has a threshold of around 2.48 volts before the shunting starts. Found in nearly every switchmode psu.

[@electronicsrepairschool]

Very well said, thank you

[@fahadahmed5294]

@@electronicsrepairschool usb meter link send me

[@mohammedamer7896]

Very nice video I have a fridge PCB where can I find the schematic for it please

[@electronicrepairservice2020]

This is a really good video. BUT - Unfortunately the TL431 smd version comes in many varieties, under many different labels - so many datasheets to look through, so how do you know which is the one you need & how do you test these (best method) ? 🤔

[@doomdylan]

It happened to me the same with a power supply board of PC speakers. I've made a reflow of the pwm controller, and looked ok for a couple of weeks.

[@gonedoneggonedoneg9863]

Era undeva ceva prins slab-contact imperfect?

[@MrRvdbeek]

Nice job , When it’s working it’s fine sometimes I do have something the same with the amplifier. Did checks multiple time. Now it’s working didn’t change something. It’s resetting or what’s happen?

[@mariuszkalwer5278]

Sorin what about checking ref on tl431 that should be 2.5 V instead od flipping this chip to and fro?

[@Radek__]

8:53 don't drink that shit, Sorin. Save your heart

[@tinkmarshino]

I have always hated that.. you go to fix something and you don't really do anything just take some parts apart and put them back together and bang.. it works! you never find that fault and you know it will come back sure as you breath.. you test it an test it and nothing.. Well I think that is the thing that makes us old in the end.. Carry on my brother..

[@tinkmarshino]

@Manjer Heibel that is an idea.. But I was talking about life in general not just electronics.. Trucks, tools, well you name it if it has moving parts I have worked on it and over my life time it has happened to many time that something that was broke just fixed it's self.. makes me crazy.. 'cause I know it is gonna happen again.. Thanks for the advice on the heating and cooling.. I am just teaching myself electronics and that is a good bit of advice to keep in my head..

[@tinkmarshino]

@@marlinnano9370 Thanks my friend.. I will certainly give that a try next time..

[@frozerinosrepairs]

Keep the good work

[@ziggy_makes_videos]

May be the solder of the ice is broken...nice one job sir...

[@boybravo689]

Sir how many voltage did you inject to the output stage and how many ohms did you expect in the output pin of the optocoupler in a normal condition

[@kintag4459]

Thanks M.r

[@Swenser]

Maybe dirty misaligned contact was the problem or a component on the verge of failing. Hope it keeps on working for your customer. A prayer.

[@sergelavallee913]

Leave it it's was a bad soldering. You fixed it.

[@Hazmoment]

Cheers for the videos sorin! Still learning lots from your channel! I have been wondering if you can help me with a question: How do you keep your Trinocular Microscope’s camera in focus and at the same magnification as the ocular lens/eye piece? I have bought a similar microscope as you for working on small electronics and i can focus perfectly in one or the other but impossible at the same time. I think i need some kind of extension piece for the Camera port? Thanks again!

[@computersrepaircotesaint-l7407]

we always like your vid

[@deeduck2038]

Even though he doesn't know about it, but likes to study, if I have Thai subtitles, it would be good. It will understand more. But will try to learn the language as well Thank you very much.

[@hugoegon8148]

Thats a pity, at begin of the video I hoped you found a fault. I had the same power supply in a different TV with same issue. TV had no function. After checking everything I soldered out some electrolytics for checking and after soldering it back the TV worked. The owner was happy, but how long will it last? Very frustrating for me. 😕

[@jmgadgetsrepairshop9040]

Thanks....

[@mikepettitt9466]

i got the same thing on the same board works ok one time then goes off wont turn on for hours then works fine been trying to fix it for some time not been able to find the fault until now

[@sebidsouza4029]

Sir I got a question out of this topic,one capacitor connected near the optocoupler one leg is connected to primary n another leg is connected to secondary side ,if I remove that capacitor then what will happen please tell me

[@therealspixycat]

Some errors occur sometimes and these are the hardest problems to solve

[@kahlid-ataya]

7:20 try using chopsticks for training 😁🥢

[@KyleSand]

I have one that everything is fine but the inverter output voltage is fluctuating on the lamp voltage and the leds light up but flicker significantly

[@hedpt]

it sounds like a capacitor problem, did you find the problem?

[@KyleSand]

@hedpt no, i suspect the optocouplers, the capacitors tested fine, not bulged or leaking

[@miftosaurus]

... i'm sure, t'is was a gremlin hand in da tv, mon! :)

[@SenorGonzales]

TL-431 sometimes can be very nasty, the chip works for many years inconspicuous, but when it fails, it fails not always complete, once it works, other moment not, a bad TL-431 chip destroyed 6 of my LiFePo4 Batterys with over Voltage, a few days ago...very "nice".

[@Androx74]

TV scared by sorin repair (TV i'm scared i'll begin to work again please don't do anything :P) joking :D, still nice to see you on with a new video always learning and even me today i repaired an old monitor that was not working anymore :D bumped capacitor i hope to see you on next video :D bye

[@loizostheochari1509]

The cause may have been a dry joint on the circuit board.

[@woj95]

Seeing that power cable connected to the PCB makes me feel little uncomfortable :D Maybe I just got shocked too many times in the past...

[@fahadahmed5294]

Hi sorin send me link usb meter

[@einfelder8262]

19:18 Ya gotta love the customer spraying his Covid particles past the face mask. Why TF does he bother to have it on his chin? It's a face mask, not a chin warmer.

[@weerobot]

Dry Joint??...That's a Weird one..lol

[@fahadahmed5294]

Usb power meter link send pls

[@trevorsmith5946]

flippin tv repairs

[@alfawasia9036]

Actully didn't get the point when checked the optocoupler by connecting a voltage to output

[@Tomtech29]

Unusual fault but the first time after connecting the TV set did not start up so the problem is still somewhere

[@miguelsanguinetti8384]

Then the customer brings back de television during the week.

[@niteshnaik2946]

Dry solder

[@intrax2tv]

Maybe you flip cause of the heat !

[@hammershigh]

flipping???

[@kahlaouimourad1588]

Sorin plz Your mail ? I have problem with hp pavilion

[@Knebebelmeyer]

looks very cheap or not complicated!! this PSU is very elementary.....

[@andreiviorel85radu64]

Meserie

[@ЗлаткоЗлатев-э5к]

Dear Sorin, please Stop drinking carbonated drinks. This will fuck up your transistors

[@electronicsrepairschool]

Sorry but i'm running on vacuum tubes :P

[@MrtechFIX254]

Second

[@kahlid-ataya]

First

[@MindYourBusiness1970]

12th

[@f.c.lalruatdika9201]

4th

[@emokeszekely8584]

Keep the good work