Most common problem on any SMPS board. Samsung LCD TV model LN52a540p2 Dead, No power repair.

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2 жыл бұрын

We have a 52" Samsung LCD TV that is totally dead with no standby light at the bottom. We will troubleshoot the Power Supply board# BN44-00200A to find the problem. Video is sponsored by www.pcbway.com/
This Samsung model LN52A540P has no power, no standby light, and no picture. So as we check the standby voltage on the power supply board/SMPS , we find out that there is no standby voltage on the plug going the the televisions mainboard. This is a SMPS (Switch Mode Power Supply) troubleshooting tutorial on how to trace back from the SMPS secondary side to the primary side to find that there is only a bad capacitor in the Primary side that is the Vcc capacitor for the Driver IC that is driving the SMPS main transformer.

Пікірлер: 41

@bigdog8882 2 жыл бұрын

You can support the Channel by making a purchase from our ONLINE STORE......bigdogelectronics.us/

@don7680 2 жыл бұрын

I'm a retired tech and really love watching your videos! You are a skilled tech and have a very nice bench setup. Thanks for doing what you do!

@bigdog8882 2 жыл бұрын

Appreciate U Brother.

@jrbird7571 Жыл бұрын

Good stuff. A SMPS is like a dog chasing his tail. I once got a job when my interviewing manager handed me a circuit board and asked me what it was. I told him it's a switching power supply. He looked surprised and asked me to explain what was going on. I showed him the primary, secondary, transistor chopping at around 50khz, the opto-isolator fed by half wave rectifier/zener diode ......blah ... blah ... blah. You know what I'm saying. He then said. "the job pays ........" and I was hired. Worked at the company for 22 years!

@edwardotoole6736 Жыл бұрын

Love watching your videos, as a retired tv engineer your videos are very informative. Teddy.

@benniedonald 2 жыл бұрын

I learn something every time I watch your videos. Great job

@bigdog8882 2 жыл бұрын

Glad to hear it!

@wisher21uk 2 жыл бұрын

Well done Marc nice fix and very well explained

@stoqntodorov3198 2 жыл бұрын

I watch you with great interest. Thanks to you I fixed the TV myself. Can you add subtitles in Bulgarian?

@rodwillett8814 2 жыл бұрын

As always, a great video.

@johnkosick1464 Жыл бұрын

I was wondering what that Cap had to do with the " Stb.. Voltage" on pin 3, because that s/b also 5V. But you explained that at the end of the video..... again, a schematic view of that failed part would have helped explain your conclusion.. Anyway, good view...... thanks!

@erichintersteiner2625 Жыл бұрын

Hey big dog Great job

@NicksTVRepair 2 жыл бұрын

Nice work as always

@bigdog8882 2 жыл бұрын

Thanks Brother Nick

@teardowndan5364 2 жыл бұрын

If you re-cap output capacitors for bulges, may as well re-cap the bootstrap capacitors too while you are already in there as preemptive maintenance since they are the next most common thing to fail. I replaced bulged output caps in both of my LG monitors ~10 years ago and had to re-repair them 2-3 years later due to bootstrap capacitors going bad. Having to re-open monitors that are held together by brittle plastic clips to change one or two $0.10 parts sucks.

@arcy070 2 жыл бұрын

Hey BigDog8882, Your videos are very informative and i've learnt a lot, I have a TV with backlight but no video and it will play sound. I've watched a few of your videos to try and isolate the issue but i'm still not 100% clear as i've not seen the exact scenario i've got. I tried unplugging one side of the Tcon at a time, each time I unplugged one side the other side would work perfectly well with a white screen the other side. If both sides work independantly but not together, what does this mean? Would replacing the Tcon board possibly fix this or is it more likely the panel? Thanks! Love your content.

@rosi6144 8 ай бұрын

Just subscribed. Best troubleshooting videos ever. I have one question BigDog, How did you learn all this? Were you in college studying electronics?, did you attend electronic courses? did you learn all this by yourself? Please explain. Hope to hear from you soon. Many thanks in advance

@bigdog8882 8 ай бұрын

Yes, a combination of aaaaall that. Thanks!

@rosi6144 8 ай бұрын

Thank you@@bigdog8882

@christop672 2 жыл бұрын

Hello sir! I've watched a bunch of your videos but unfortunately if this problem was mentioned in one of the, I missed it. I have a UN65mu6300f Samsung TV and I suspect the mainboard is dead. However when I power the supply, STBY measures 9.5v instead of the 7.5v written on the powersupply. Would it be what killed the mainboard so I should replace both at that point? Thank you for doing these videos and answering the comments by the way. I'm glad someone's still interested in repairing stuff instead of throwing it away.

@Luka7517 2 жыл бұрын

Love the video, only question I have is what tools you use and where can we get them, tools like voltmeter and soldering iron, etc...

@mangist Жыл бұрын

He did a whole video on his workshop setup, worth a watch.

@meTimetraveler Жыл бұрын

the one i have like that was made in 2008, should have the manufacture date on the label. can you short the caps on the hot side w/o it damaging anything?

@doug4840 2 жыл бұрын

I've noticed you use the CEM DT-9989 multimeter but it's $500. What is a good meter to use that is less expensive. Something that will also check capacitors in circuit? Great Videos, keep them coming.

@bigdog8882 2 жыл бұрын

I have a half a dozen meters and thats the only one that check caps accurately in the circuit, but you can get any multimeter with a cap tester and/or get an esr meter too. Those capacitors in the primary side dont have much in the same circuit to disrupt the reading.

@edwardanthony7283 2 жыл бұрын

Panasonic had capacitor issues with vcr/dvd players causing it to go dead as well. Fixed it then a week later it wnt dead again with same issue! JUNK!

@johnb5896 Жыл бұрын

Hi have you had any tvs with just a Blue screen thank you

@kenpappas9520 2 жыл бұрын

Is 12vts delivered from the main TO the ps? I get standby, turn on, logo flash, but no 12vts. Thanks and keep em coming!

@bigdog8882 2 жыл бұрын

The 12v is coming from PS after the main sends the PS ON command(voltage). So if your getting standby and the Power ON voltage but the 12v is NOT coming up; then u have a bad PS board. Just trace the 12v pin backwards to find out why...

@scottmaurice6008 Жыл бұрын

Hey Bigdog. I've seen your videos where you replace the individual LEDs. How do you know the part number for the individual LED? Where do you get them from? The LED strips ate kind of pricey. I'd much rather solder one led back on the strip for a tv that isn't that old.

@bigdog8882 Жыл бұрын

just google "individual led for TV backlight" should be 2835smd or similiar.

@scottmaurice6008 Жыл бұрын

@@bigdog8882 thank you

@richardgillen696 2 жыл бұрын

Hey bigdogg! I have a element E4SJ5517BF and my issue is the tv will come on with a image and then a few minutes later it has no image but the backlights are on. And I can hear the audio going. So I was wondering if you ever ran into any issues with this model.

@bigdog8882 2 жыл бұрын

Check/Wiggle the LDVS Cable going to Tcon from MainBoard.

@Livbestlife 10 ай бұрын

what up my brother, good work, i used to do this type of work early in my career, early 80s, now I used my skills just to help isolate the problem. I have a BN44-00629A board from my Samsung 55 TV, the issue is it just recycles, and plugging in just power supply no cables it just clicks. Are you still doing repairs?

@bigdog8882 9 ай бұрын

Yes.