Tv repair - switching power supply TL431 feedback circuit
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- Опубликовано: 28 авг 2024
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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.
This video wasn't pointless - it was real live. Thank you!
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
17:57 your coworker is really jamming to some crazy beats ;)
m.ruclips.net/video/TYXHv97kbps/видео.html&start_radio=1 to be more precise
hahahahahaa
Its actually around 60VAC
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!
thank u so much sorin. you are right it s very common problem but you are the furst to explain it clearly. thumbs up!!!
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.
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.
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
some times there is a magic in electronics
Thank you Sorin. Stay blessed man 🎊😼🥀🌷
In Mexico, when it looks like a device repaired itself, technicians say: "It was afraid of me"
great work Soring :) even the TV gave in to your superior repairs :)
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 :)
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
Perhaps the heat revived the component.
@@MatiusLenin The culprit perhaps is a cold joint....
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
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
Thanks nice video solve problem smps
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
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.
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.
Very well said, thank you
@@electronicsrepairschool usb meter link send me
It really brightens my day.
A thousand thanks for this beautiful instructive video
I realy like ur video sir
Im from phillipines ... mindanao
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) ? 🤔
May be the solder of the ice is broken...nice one job sir...
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?
maestro buenos dias desde Mexico!!!
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.
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. 😕
So good Sorin .. thank you so much 😃😃
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..
@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..
@@marlinnano9370 Thanks my friend.. I will certainly give that a try next time..
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.
Leave it it's was a bad soldering. You fixed it.
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
Very nice video
I have a fridge PCB where can I find the schematic for it please
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!
Keep the good work
Sorin what about checking ref on tl431 that should be 2.5 V instead od flipping this chip to and fro?
Some errors occur sometimes and these are the hardest problems to solve
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
Thanks M.r
we always like your vid
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
8:53 don't drink that shit, Sorin. Save your heart
Are the diodes at the output the schottky diodes? Whats the part replaced around 10:00 part?
The cause may have been a dry joint on the circuit board.
Era undeva ceva prins slab-contact imperfect?
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
it sounds like a capacitor problem, did you find the problem?
@hedpt no, i suspect the optocouplers, the capacitors tested fine, not bulged or leaking
Thanks....
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".
Dry Joint??...That's a Weird one..lol
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...
Then the customer brings back de television during the week.
... i'm sure, t'is was a gremlin hand in da tv, mon! :)
Hi sorin send me link usb meter
7:20 try using chopsticks for training 😁🥢
Actully didn't get the point when checked the optocoupler by connecting a voltage to output
flippin tv repairs
Unusual fault but the first time after connecting the TV set did not start up so the problem is still somewhere
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.
Usb power meter link send pls
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
looks very cheap or not complicated!! this PSU is very elementary.....
Maybe you flip cause of the heat !
Dry solder
flipping???
First
Sorin plz
Your mail ?
I have problem with hp pavilion
Dear Sorin, please Stop drinking carbonated drinks. This will fuck up your transistors
Sorry but i'm running on vacuum tubes :P
Second
Meserie
12th
4th
Keep the good work