Samsung TV , Clicking ? Dead no power ? PFC common fault repair to component level .

[@austingraves3425]

I was a TV engineer from '56 and retired just as flat screens were coming in. Its nice to see you repairing down to component level, as we did. Very good video 😊

[@michaeldranfield7140]

You retired just at the right time then, no money to be made on TV repairs anymore, the CRT days were by far the best.

[@lawrencejelsma8118]

​@@michaeldranfield7140... The problem also is repairing a CRT TV today also. Even having a working digital signal converter to analog signal box, a fixed CRT of say $50 for parts and labor (as a new HDTV of CRT screen size can be $200-$350 in the U.S.) there is risk of further breakdowns of electronic components barely getting by. Even nostalgic computer gamers saying they are spending $200+ in the U.S. on nostalgic old CRT TVs now getting 16+ years old as the beyond warranty last engineering designed day of that TV for lasting longer like a brand new TV. Having to buy a $200 nostalgic 32 inch TV max, 16+ years old, is not worth the risk as figuring out an advantage of buying a new TV of High Definition like this fix on this KZbin video at hopefully less than $75 in the U.S. as a brand new 55" of this same model is only $369 brand new and with new warranties.

[@nightlore000]

I used to work for Rumbelows 1974 Service engineer down to component level .. left the trade in 2003. Thanks for posting .. There's not many engineer's now, they're just fitters ..

[@michaeldranfield7140]

@@nightlore000 the official take is now to just replace the whole board , there are no schematics for these boards .

[@myat.oo1oo90]

Thank sir.your explain schemetic drawing is very good.

[@toolsarecool]

Brilliant diagnosis, explanation & repair. I’ve never watched any of your videos without learning something new. Thank you for sharing your lifetime of experience here! 🙏

[@michaeldranfield7140]

Thank you for that.

[@stevejagger8602]

Skimping on a resistor wattage that basically has no value. Thank you for the insight and circuit analysis. This is how we learn - by sharing knowledge.

[@michaeldranfield7140]

Makes you wonder if it's deliberately done so the set doesn't last.

[@stevejagger8602]

@@michaeldranfield7140 I think that is very likely - profit drives this disposability.

[@dennissmith8199]

Michael, you are the TV repair wizard! Great job and video.

[@michaeldranfield7140]

Many thanks for that.

[@philipmnkydusdtbreeze5024]

DPRTRD IT AARRRRRTTTT WELL DONE​@@michaeldranfield7140🤐

[@ralphj4012]

Well explained and repaired. When you have a spare moment (ho, ho), as other have suggested, it may be worth measuring the drop across the 10R resistor to determine what current is flowing and how under-rated the previous resistor was.

[@michaeldranfield7140]

Sets already gone back but I can try that next time I get one.

[@alasdair4161]

From the initial diagnosis there was 15.1V on the transistors emitter, if the PFC chip is expecting 12V the three volt difference equates to 0.9W which seems strange especially as the 15.1V was not a fully unloaded reading so probably close to the correct voltage considering the transistor was also dissipating around 2.4V with the 3V difference from it's collector. Maybe the PFC chip runs higher than 12V nominally but requires it's initial start current to not pull it any lower than 12V (cap charging etc). That could explain the resistor's reason for being there.

[@ralphj4012]

@@alasdair4161 Indeed, hence the suggestion for a little more diagnosis if another set comes in. We can determine that 900mW was being dissipated (in whatever state the PFC was in) and that is clearly way too high for the original and replacement SM resistors. I suspect (I hope) that when the PFC is running that there is very little drop across the resistor. The issue may be that the designers did not account for a pre-start or PFC failure situation (no design can accommodate every potential component issue) As an aside this in no way diminishes the work that Michael performs (which way exceeds my skills).

[@AeroGraphica]

Could it be the zener that was out of specs, hence the 15v and the resistor eventually failed due to higher dissipation than planned ?

[@alasdair4161]

@@AeroGraphica They can fail that way. I've even had zeners adopt a strange thermal drift characteristic that makes the fault really interesting to diagnose.

[@markpirateuk]

Amazing it was just a tiny resistor! Brilliant troubleshooting, as usual, a master at work😁

[@michaeldranfield7140]

This set was another one of the lucky ones!.

[@angelosanagnostou5550]

Thanks Mike, very informative. I had the same kind of issue on a different set, the PFC circuit. When heating up the board with a hair dryer then the pfc circuit started working. I turns out that the little electrolytic cap that smooths out the vcc supply to the pfc ic was high esr. That took me 5 hours to discover

[@michaeldranfield7140]

I did look at the caps in this set as they were very small and looked like they were designed to have a short life but in the end they were all OK.

[@angelosanagnostou5550]

@michaeldranfield7140 Can you perhaps advise me on a panel issue? I have a Samsung UA55NU7300K with a failed panel. You posted a video on this but there is a difference I wanted to discuss with you.

[@DaveBrown1]

Well done that man, all understood. Inbuilt obsolescence, underated resistor and after 5 years it's time to buy another TV. Great video and thanks for the share 👍

[@michaeldranfield7140]

It does make you wonder if components are underrated why they used them in the first place , could well be built in obsolescence as you say .

[@danmyers7827]

@@michaeldranfield7140 Exactly. I would expect that the designers have the necessary knowledge to make the right choices for components. Then there's the CAD software they likely use; that can make the calculations too. I have heard about electrolytic capacitors in flatscreen TVs being deliberately underrated in terms of operating temperature. 85°C fitted where 105°C is needed for a decent service life. When failure occurs after 4-5 years, the TV is thrown away. More turnover for the manufacturer, more waste for the planet. To do things right would cost €1 or less per set, at mass production prices.

[@omidmahdavi9777]

Really great, you identified this problem, your work is great👏

[@michaeldranfield7140]

Many thanks for that .

[@diyfixtool830]

Your workmanship is great PFC common fault repair to component level

[@benben00981]

Congratulations mate!! The old skilled technicians are gone!! We have just scrap now.. Appreciate tour video. Very educational for us as young leaners

[@michaeldranfield7140]

this is a skill that will be lost soon as everything is getting disposable now .

[@bcu567obzx]

Thanks Michael for your you tube fault guide, I have a Samsung with the same clicking noise and replaced the SMD with a 10ohm Metal 1/4 watt resistor and the set works just fine, thanks ever so much for your help, parts cost 85 Australian cents.

[@michaeldranfield7140]

No problem at all , glad I could help .

[@Knebebelmeyer]

i had a similar one few years ago and i tryed hours of hours of toubleshooting and change components,but i was not able to fix it! i was so mad about it, that i dont want to buy a replacement PSU! it was 75$, so not that big, but my frustration was so high, that i refuse to work any longer on this tv! very good job

[@michaeldranfield7140]

Its not easy trying to find a fault without a schematic diagram but cheaper than a new board , especially when you have the same fault more than once .

[@Fastpia]

Thank you for helping me. Replaced 10ohm because mine have 48ohm. (100). Tv turn on and works for a day already. No troubleshooting. You are master!

[@michaeldranfield7140]

No problem , many thanks for watching .

[@carlilemike]

Great video Michael. I noticed the 10ohm res had a zero ohm link in series. Maybe originally they specced two 4.7ohms resistors in series but the bean counters won!

[@michaeldranfield7140]

Quite possibley and the zero ohm link resistor was much larger!

[@marksntl7632]

Most Excellent Michael! 👍Good to see you again in action 👍Thanks for sharing this with us all! 😎

[@michaeldranfield7140]

still going but summer time is a very quite time for TV repairs , might try some vintage stuff next !

[@ElectronPcRepair]

I love your work pls continue teaching the world. Thanks

[@michaeldranfield7140]

More videos coming but they wont always be LCD tv repair , I have loads of vintage stuff I need to repair soon .

[@ElectronPcRepair]

@@michaeldranfield7140 sorry for my poor English, but the way you identify and clarify , resolve and teach present is clear and not forgettable. God bless you. Josey

[@michaeldranfield7140]

@@ElectronPcRepair wouldn't be any fun just fitting a new board .

[@wisher21uk]

Brilliant Michael, excellent walk through off the repair clear and precise thank you 😊

[@michaeldranfield7140]

Many thanks for that.

[@kerryp1525]

Nice bit of knowledgeable trouble shooting ! Not Many techs can actually do this degree of diagnosis ! I'm sure you've run across your share. (of techs ). Nice to see a proper analysis ! Thanks !

[@josephbonello163]

love your Work Michael..learnt a lot from your youtube channel

[@michaeldranfield7140]

Many thanks for the comment and for watching .

[@oscarmarfori613]

9:38 that was clever I never thought of that using the iPhone as a microscope I was already contemplating on buying a dedicated one, thanks for that wonderful idea 👍

[@michaeldranfield7140]

im amazed how good the phone is , far better than the Chinese microscope I bought which is absolute crap .

[@oscarmarfori613]

@@michaeldranfield7140 Because of your Brilliant Idea, I will just have to purchase a “phone holder arm” that I can just clamp the iPhone into saves me more money for not buying the electronic microscope, it’s a win Mate 👍🏻 thanks again for sharing your brilliant ideas

[@michaelclutton8446]

Amazing repair, I imagine if 100 TV had that fault 99 of them would have been scrapped

[@pizzablender]

I remember these CDs and web sites with repair instructions. "Sony TV chassis xxx turning on slowly with green line at top of screen, remove screw of lip holing PCB at the front, break way plastic lip, re-solder the voltage regulator". That's literally how I remember that. And indeed that fixed it, turned a 3 hour search into a 10 minute repair.

[@michaeldranfield7140]

A new board would have fixed the problem but that's no fun, first time I had this fault it took hours to fix with no service manual.

[@manclt704]

@michaeldranfield7140 I used to perform component-level repairs on electronic equipment during the 1970s, and it's wonderful to see that there are still a few people capable of doing this today. Excellent video, thank you for sharing!

[@michaeldranfield7140]

a good understanding of how these systems operate is useful but the problem with new sets is there are no schematic diagrams so most of the time its more good luck than knowing what your doing, the official thing to do is just replace the whole board but usually this cost more that most sets are worth .

[@manclt704]

@@michaeldranfield7140 Yes, you are right. Back in those days, detailed schematic diagrams were available for almost all TV models. This meant you didn't have to rely on reverse engineering or guesswork; instead, you could scientifically troubleshoot and fix the issue. Thanks

[@michaeldranfield7140]

@@manclt704 its very sad the makers wont release any schematics, they must have them from when they design the set on a drawing board .

[@englishrupe01]

Great job, Michael.....thanks for the show.

[@michaeldranfield7140]

Many thanks for that .

[@engineernaeemaftab]

Best teacher ❤️

[@michaeldranfield7140]

Many thanks .

[@radio-ged4626]

Great tip Michael, that's a massive time saver.👍👍👍

[@michaeldranfield7140]

It's well worth remembering, I have had this same fault quite a few times now on different models.

[@Dave64track]

Just come across your channel that was a great down to component level repair I have just subbed keep up the great work.👍

[@michaeldranfield7140]

Believe it or not I don't do that many TV repairs these days, most people just prefer to throw them away and buy a new one .

[@kevb1816]

Good vid Micheal! Why on earth didn’t they fit the higher rated resistor in the first place - SMD resistors aren’t exactly expensive and the difference between the 2 sizes must be tenths of a penny…

[@manolisgledsodakis873]

I've worked in industry so I can tell you the possibilities: 1. one million TVs manufactured and a saving of one tenth of a penny per set adds up to 100,000 pennies or £1000 pounds. It's not a huge amount but if you can do that with several components it adds up. 2. A TV only has to last the warranty period so, if you make it fail after the warranty expires, that's a new TV sale. 3. the specified component was out of stock so someone used the next nearest "equivalent". 4. the original designer didn't bother to do the maths or made a mistake. 5. the resistor was from a bad batch. 6. glue or other contaminant caused the resistor to corrode (not in this case but a common problem).

[@austingraves3425]

Then we wouldn't have this video😊

[@michaeldranfield7140]

Given that these was space on the pcb to fit a bigger one this could have been a deliberate act to make sure the set didn't last too long but someone has also given a whole list of reasons it could be.

[@stevebabiak6997]

@@manolisgledsodakis873 - although I do agree with all of your possible explanations, there is one that might make more sense: the zener diode at the base of the pass transistor is no longer operating properly, and is at a voltage higher than it’s original nominal rating. Thus the voltage at the emitter of the pass transistor is too high, pushing more current flow to the load. A measurement of that zener voltage compared to its nominal voltage should answer whether this is the case or not. If not, then maybe that 10 ohm resistor was improperly specified in the design.

[@renowden2010]

The culprit is not really the 10R but Samsung for not using a component of high enough rating.

[@michaeldranfield7140]

And given that there was space to fit a much larger resistor it does make you wonder why this was done in the first place.

[@waynewayne3709]

To save money and get away with it, oh and then sell us a new tv .I stopped repairs on tvs in 2004..on wide-screen sets.. I've done a few over the years but don't have the time anymore.

[@michaeldranfield7140]

@@waynewayne3709 technically speaking repairing TV s should be very easy now , just fit a brand new board and away you go , the problem is boards are so expensive no one wants to pay , so where ever possible I always look for the fault first , new board is last resort.

[@FrankJCarver]

I think we have a bit of 'planned obsolescence' going on here. Google planned obsolescence, if you don't know what it means.

[@oladunk9986]

Samsung uses underrated capacitors in their power supplies. I have see this problem in 19 inch PC monitors to big TV sets. Since back in 2005 when I purchased my first 19 inch flat pc monitor.

[@michaeldranfield7140]

you don't see anything now with good quality capacitors like you use to in the 70 s and 80 s .

[@lukasgayer5393]

This was absolutely brilliant! I´ve learned so much from your video! Thank you.

[@michaeldranfield7140]

it might just save you from buying a new board .

[@TechRoady]

This was a great learning experience for me thanks for sharing the knowledge.

[@michaeldranfield7140]

No problem , many thanks for watching .

[@TermitesRGood1]

Samsung makes to easy to Diagnose their TVs,If you disconnect Main board and it Turns on its your Main board Replace or fix if you know how if it still doesn't turn on its your Power board .Theyre the only ones that do this in the industry Cheers :)

[@michaeldranfield7140]

That's the only good thing about Samsung but you still don't want to jump to conclusions, in this set with the main board disconnected the backlights were flickering which might lead you to think the backlights were faulty when infact it was the PFC not running .

[@ppdan]

For those wondering why a "100" marking is 10 Ohms. ABC -> AB . 10^C (so C is the number of 0 you have to add to the first 2 digits) 100 -> 10 . 10^0 = 10 . 1 = 10 102 -> 10 . 10^2 = 10 . 100 = 1000 = 1k 476 -> 10 . 10^6 = 47 . 1000000 = 47000000 = 47M

[@michaeldranfield7140]

I always assumed 100 was 10 plus another zero same as capacitor marking but thankyou for the explanation .

[@renegeijtenbeek7457]

Hi my friend. I have a ue55d7000 and the same problem... Super to know where to look new. Thank you master😊😊.

[@michaeldranfield7140]

No problem , many thanks for watching .

[@proluxelectronics7419]

On the fiat 500 led leak failure, Fiat motorhomes, same issue. Had a few in for repair, 80 quid a pop, pointer off jobs, no problem.

[@CriticalThinker84]

Where in the country are you? Would be interested if you could fix a 500 cluster.

[@proluxelectronics7419]

@@CriticalThinker84 North-east.

[@trebel]

Thank you for all your hard work. Thank you kindly. Good tutorial. Cheers m8.

[@walker55able]

Great fault finding Michael

[@michaeldranfield7140]

No problem , many thanks for watching .

[@joseguadalupecadenamunoz6340]

Un televisor mas con una segunda oportunidad gracias a esta excelente reparación 🧐

[@manolisgledsodakis873]

"One more TV with a second opportunity thanks to this excellent repair"

[@michaeldranfield7140]

Just another of the lucky ones.

[@5pr1nk57]

Btw you've got yourself a new sub! 😊 Great diagnosis and explanation and good to see another fellow tech/electronics enthusiast here in the UK! 😊 You sound as though you're from Leicester or further north, Yorkshire perhaps? I'm down south in Surrey 😊

[@michaeldranfield7140]

No Im from Buxton in Derbyshire , I have always been in the TV repair business but repairs are getting few now everything is so cheap brand new .

[@-MrDontCare-]

Good job and well explained troubleshooting.

[@michaeldranfield7140]

No problem, many thanks for watching .

[@truthreigns7]

Wonderful and educational, thank you

[@michaeldranfield7140]

Many thanks for that .

[@ianlee487]

What a clever guy great watching you

[@michaeldranfield7140]

Many thanks for that .

[@Trucam2020]

Excellent repair video. Thanks

[@michaeldranfield7140]

No problem , many thanks for watching .

[@arifryo6823]

sir, what app you use for magnify for the phone please.

[@michaeldranfield7140]

Dont have an app , its just the camera on the phone .

[@reacey]

I did one of these recently with a faulty opto- coupler. Im guessing when you soldered those wires onto the resistor , it partially rectified a defect inside the resistor hence the 30 ohm reading ..iv seen heat from desoldering components temporarily "fix" internal open circuits in components before , must be the thermal expansion of the metal inside causing breaks to become bridged back together

[@5pr1nk57]

Hi, can I ask if it was the same PSU as here that you found the faulty optocoupler? I currently have one of these PSUs I'm trying to repair and have no V on rails or backlights. The resister that's the culprit here reads ok and I have 15-17V from the Aux winding on the SB transformer so was beginning to suspect the optocoupler? 🤔

[@reacey]

@@5pr1nk57 it was very similar to this psu. Ive done 2 the same board recently , one had a dry joint and one had a bad opto-coupler, it was reading about 300 ohm on one side of it with the probes either way round which is why i suspected it , the other optocouplers all gave similar readings in ohm mode and diode mode . Id just change them all and then you can rule it out .

[@reacey]

@@5pr1nk57 after looking at this video again im sure its the same psu. I first thought the fault was the 7 pin chip on the primary because it was getting warm but nothing else was and there was no output on the secondary . Its a pwm/mosfet ic, i bought one from italy and changed it and it did the same thing which is why i started looking at the surrounding standby circuitry and optocouplers etc

[@5pr1nk57]

@@reacey I've actually since found the fault! There was a small 2A ceremic fuse hidden under some gunk that was open and it revealed a short on the latter part of the primary side which was 2 Smd Mosfets on the reverse of the board so just have to pick some up now as no stock/donors here :)

[@michaeldranfield7140]

It could very well be , I have found in the past many a diode that reads faulty in circuit then works perfectly after its been desoldered.

[@Barbarapape]

A classic example of fitting underated components that sooner or later will fail. We were trained to fault find to component level, today it is just to board level which is very wasteful. What will happen when our generation has gone?

[@sw6188]

Like you I was trained to component level. If we had even suggested the possibility of replacing an entire board the service manager would have fired us on the spot! These days as you say it's all about being a board jockey. Even I have had to resort to doing that, in a situation where an electrolytic capacitor had leaked onto the PCB causing the high voltage present on that cap to track over the board then start arcing then burned a large hole in the board. It was beyond repair as it was a multi-layer board, so I contacted the company and the solution - "replace the entire board". They sent me a complete replacement. I don't know what the future of electronics will be when we are gone. Very likely there won't be any servicing, people will just toss their broken appliances and buy a new one because they will be so cheap - much like how it is now, except we still have people repairing some things today.

[@Barbarapape]

@@sw6188 This is the way the world of electronics has gone, and consumer electronics has been steadily turning into a throw away situation since the 80's. I can remember asking for a service manual for a Philips radio cassette to be told that there wasn't one or any parts stocked to repair it, if they failed under warranty they just replaced it. One option is to make the items self repairing, once the last of the good circuits have blown , then it item is scrapped. I first came across this technology working on the Euro Fighter, they had three backup circuits for the critical controls when i pilot reported a fault we just ran some diagnostics and replaced the faulty module, but not the faulty component. This is all paving the way for everything going AI, then no one will be needed!

[@5pr1nk57]

I'm in my early 30's and like to fualt find at component level rather than just replace boards. Learning all the time! :)

[@sw6188]

@@5pr1nk57 Good way to go, it will stand you well in the long term.

[@Barbarapape]

@@5pr1nk57 A skill well worth having, spare boards are not always available, but components are easier to find.

[@electrolatif]

You are genius, i learn new things today. I am so happy 😊 Appreciate

[@derekblake9385]

Great job, another one saved from the tip!

[@michaeldranfield7140]

Many thanks for watching .

[@pauldavies6037]

A 1/16 watt resistor would be interesting to find out the switch on and running current in that little circuit a design error there !

[@michaeldranfield7140]

could be built in obsolescence, a trick to ensure the set does not last too long .

[@pauldavies6037]

@@michaeldranfield7140 Yes any SMD IC or transistor or resistors current ratings are too low will fail

[@558vulcanxh]

Very good indeed Mike😊

[@michaeldranfield7140]

Many thanks for that .

[@gordonemery6949]

Cracking video again ,ive got a sharp tv and its starting to have little glitches whenits warmed up,i think ill let it develop lol before I operate 👍

[@michaeldranfield7140]

With anything intermittent its best left to develop, you might even find it will throw up another clue where to look if the fault gets worse.

[@rayfiore7779]

I have a 55 inch Samsung UN55RU8000FXZA and it has a similar failure. 1) The standby light flashes momentarily when I try to turn on the TV but there is no picture/ sound/ or backlight. 2) The 3 electrolytic caps on The Power Supply Board at the top left ( near the o/p to the main Board) have 'domed' tops. 3) When I unplug the Main Board from the Power Supply Board the Backlight turns on. 4) The Main Board does make a sound at turn on like a 'Flyback Transformer' (but only for a moment). My first thought was that the Main Board has a short that is drawing down the Power Supply & keeping the Backlight from turning on. But the other possibility is that the Power Supply Board can't source the current to the Main Board. 5) Additionally, I disconnected the 3 output cables from the Main Board & the backlight is still not lit. Have you any suggestions?

[@rayfiore7779]

Bad Caps on the power supply output 470 microfarad 25Vdc

[@Chris558576]

Thanks for this, worth knowing as i have a Samsung tv here as a monitor on my pc.

[@dimitrismaster]

I have a question about this pfc .SInce a rectified voltage is Ac X Sqr2, in our case its 230 X 1.414= 324 V dc.What boosts further the dc voltage to almost 400V DC ?

[@michaeldranfield7140]

It's the power factor correction circuit that boosts up the rectified mains.

[@dimitrismaster]

@michaeldranfield7140 there must be a coil for a boost converter that I did not notice.Or a winding on the main chopper?

[@michaeldranfield7140]

@@dimitrismaster correct , there is an inductor .

[@stevekim3922]

Hello Michael, I like to know you have Philip chip R storage bin (container) in video. I like to know where I can get those organized Chip Plastic Bin. Please let me know. Thank you.

[@michaeldranfield7140]

Someone else asked the same question , this kit was made by Philips to aid repair of the new G90 and G110 sets of the 1990s which were one of the first sets to used SMD components , so its getting up for 30 years old now , the only place you are likely to get one of these is on the internet where someone has closed a shop and selling all the old kit off ., I also have the transistor and capacitor Philips kit .

[@stevekim3922]

@@michaeldranfield7140 Wow! 30yrs Old Product. You has been keeping and clean used it. Thank you.

[@dimitrismaster]

Sometimes ,especially on some older samsung or lg sets,just resoldering the st by and main chopper transformers solves this issue.Cold solder joints can be the issue of relay clicking and no power on.

[@michaeldranfield7140]

Dry joints seem to be much more common on equipment using leaded solder than it is now but yes I have had loads of Samsung in the past with dry joints on heats inked components.

[@darkwaxer]

Interesting stuff, thank you. I’m currently trying to diagnose a Samsung N87 from 2007. Replaced the caps (well the starter round black ones), no joy. Checked standby voltage and it’s clicking 1.8 to 13v.. standby should be 5.3

[@hooperwille]

I have very similar situation, did you find the problem?

[@Jetta-Liner]

Nice to see this Video,,,i ve same Problem , n fixed them,,,but i need longer time,,,,thx for learning,,Mike

[@dianeog1]

Quite enjoyed that video.👍👍👍

[@michaeldranfield7140]

Many thanks for that .

[@jamescrawford2042]

Great job again keep up the good work

[@michaeldranfield7140]

Many thanks for that .

[@mixolydian2010]

Thanks a lot for the tip, take care.

[@michaeldranfield7140]

No problem , many thanks for watching .

[@iancooper2338]

Great job MD! 🙌

[@michaeldranfield7140]

Many thanks for that .

[@gainmaster1]

Keep the content coming Michael

[@michaeldranfield7140]

more coming but might be something vintage next time !

[@linedancer111]

Really well explained thank you!

[@michaeldranfield7140]

Many thanks for that .

[@WinrichNaujoks]

wow amazing repair!

[@michaeldranfield7140]

Many thanks for that .

[@Swenser]

Cool bananas. Can u recommend a video that explains well the pfc circuit in a tv

[@michaeldranfield7140]

Have a look round the internet for { Power Factor Correction } this should tell you what you need to know .

[@minimylk]

You sir, you're a genius!

[@mpaisensei8728]

super amazing skills sir michael new sub here. I hope to learn more from your videos..thumbs up to you

[@michaeldranfield7140]

Don't get too excited, there is no service manuals for most sets now so a lot of fault finding is just down to good luck , unless you just replace the whole board like the manufactures want you to do .

[@richb419]

Hi Michael, do you think the resistor was sized for a fusible link? more than likely it was selected to shorten the life of the TV ( engineered obsolesce) Rich

[@michaeldranfield7140]

Could well be built in obsolescence and deliberately designed to fail , not easy to find the first time I had this fault as there is no schematics for most sets now .

[@turboslag]

Just shows, experience counts! Michael, where can I buy that smd resistor selection box, and is there a capacitor version?

[@michaeldranfield7140]

Yes there is a capacitor selection box also, I very much doubt you will buy one of these now though, these were produced by Phillips for repairing the G90 and G110 sets of the 1990s.

[@turboslag]

@@michaeldranfield7140 That's a shame, ah well, thanks anyway Michael. Really interesting to see component level repair like this, and good that the set was saved from a premature end👍

[@michaeldranfield7140]

Keep an eye on e bay with so many shops closing down you may come across one .

[@OaklynHall]

Thank you for sharing this interesting and educational video with us. Please may I ask what makes the resistor increase in resistance?

[@rpsmith]

Normally overheating but in this case, probably just poorly made part.

[@dimitrismaster]

Many resistors fail to open circuit,but many fail to very high resistance.

[@ElectronPcRepair]

Thanks 🙏

[@michaeldranfield7140]

No problem , many thanks for watching.

[@adalbertus777]

Great video and troubleshooting masterpiece, Michael. Thank you for sharing. Can I ask , how much time does it usually take for you to get into the right place like for example in this case?

[@michaeldranfield7140]

The first time you do it it can be hours, or sometimes I look and cant find the problem and put it to one side and comeback another day , all this could be avoided if there was a service manual with schematic diagrams like there use to be years ago, now you have to look for datasheets on the internet for specific chips to set an idea of how a chip operates.

[@adalbertus777]

@@michaeldranfield7140 Thank you. Priceless your are so keen to share your findings with rest of world.

[@paulsanderson8804]

Excellent video Michael as per usual what would you say causes these resistors to fail would you say heat has a part to play?

[@michaeldranfield7140]

I think the resistor fitted was far too small and there was space to fit a bigger one, I wonder if it was designed to fail in the first place.

[@paulsanderson8804]

@@michaeldranfield7140 I think manufacturers should not be allowed to do these tricks shame on them

[@blurtmenow]

on your next video could you show how you had the phone set up as a microscope? Was very impressed as to how stable and clear it was. got some old phones i could put to use haha.

[@andreaslundstrom5743]

Good work thanks for the tip

[@michaeldranfield7140]

Many thanks for that .

[@naeemn45]

Hi Michael, Nice methodical way of finding the fault. Can you make videos on oled tv?

[@michaeldranfield7140]

I have only ever had two OLED TV s in for repair and neither customer had them done due to the very high cost of new boards .

[@Jason-zh7wo]

Awesome, thanks for the info 👍

[@michaeldranfield7140]

No problem , many thanks for watching .

[@Hilbohead]

I'm a year older than you and remember reading Everyday Electronics and ETI as a great read! I have a Samsung UE32T4307AK (so a single pcb, newer gen.). I was interested if you had had one to look over yet? This one doesn't power up, but the front telltale LED is on for about 5 seconds, goes off fleetingly, then straight back on, over and over. The PFC route sounds interesting! There is 331v across the main cap. There isn't an S3050 PFC chip that I can see, but there is a 4801A chip, which does have 13v going to it. There are loads of similar, working spare boards on eBay. I think there is a lot of demand! Maybe the panels die early and these TVs get broken for spares? A briefly-borrowed pcb from an identical neighbour's TV fixes it completely. Do you know if this is a 'standard' problem, hopefully with a 'standard' easy, fix! TIA Great videos, BTW!

[@marializianichols648]

A simple switching pathway became complicated... I'd use a simple method to do that with the opto coupler and 2 tiny MOSFETs without zener diode without resistor .

[@michaeldranfield7140]

made even more complicated by not having a schematic diagram.

[@tubeDude48]

Nice catch!

[@michaeldranfield7140]

Many thanks.

[@paparoysworkshop]

I have a 55 inch Samsung that kept rebooting. If you disconnect the cable to the screen, it stays on. Further investigation found that on the circuit board attached to the bottom of the screen there is a 10 pin chip marked with the letter "D" on the board. I assume it's a diode pack. The chip is marked as 4268H but can't find any information on it. I removed the chip and the TV works fine without it. I'm still looking for a replacement chip as it was put there for a reason. Perhaps some kind of back EMF protection as it appears to be installed reverse polarity. Without schematics, it's difficult to be sure and I don't want to waste hours trying to reverse engineer it. If anyone knows about this chip, I would love to hear from you.

[@michaeldranfield7140]

at a guess I would think its some sort of transient suppressor diode array but I think the only place you will find one is on a scrap LCD panel .

[@paparoysworkshop]

@@michaeldranfield7140 You are probably right. I have salvaged other Samsung 55 inch TVs looking for it but they were different model numbers and used different components with different pin counts. 6 pin seems common but I need one with 10 pins. I'm sure they do this on purpose just to make it difficult for DYI people to make repairs. So I most likely need to find the same model number. The TV works fine without this chip, but will some stray voltage destroy something else one day if I don't replace it? Who knows!

[@ericbraman]

Is there any way I can DM you directly sir? I've got a late model Samsung q60 model TV with similar behaviors to this television. However, it is an edge lit strip. The entire LED strip seems to be strobing on and off. If I disconnect the leads to the white LEDs, the blue LEDs come on. If I try to connect both the blue and the white, the strobing starts again.

[@andygozzo72]

hmm if 12 v at the pfc chip, and output of the transistor is 15v, that means 3v across that resistor, meaning 0.3amp through it, 0.9w dissipation , ?! no wonder it fried! did you measure the actual working voltages at the pfc chip?

[@michaeldranfield7140]

I didn't measure the voltage at the chip which was a mistake but some chips have an internal zener diode on the Vcc so this may account for current draw .

[@BjornV78]

Who knows how many TVs were thrown out just because of this faulty little resistor. I also noticed that the voltage over the 450V caps was very fluctating, is that normal ?

[@michaeldranfield7140]

it should be reasonable stable , it could well be me holding the probes as well at the camera .

[@Flexible_Ketchup]

❤ Great job brother 🙏

[@ErnieSesameStreet]

I have two samsung tv of the same model. One of it the display panel is spoilt but the speakers are still working. Can I add the speakers into the other TV and in total have four speakers?

[@TerryDeSimone]

This video is ALL the information i need for a 60 inch Samsung... but the video is blurry.. you didn't show where these components were on the other side of the board, and where that lil resistor was even located, in what area..

[@michaeldranfield7140]

you have to download the datasheet for the pfc chip and then you can trace it back from there .

[@shauntaylor9144]

HI Michael i have samsung ue40f7000st with bn44-00632a psu board, it as low pfc 355v where shoulld i be looking for this fault, many thanks

[@spazmochad]

Did you buy a lens for your phone to enable the microscope? Are you able to solder using it? 😮

[@michaeldranfield7140]

No lense, it's just a £200 Huawei phone, the picture from the phone is 10 times better than a cheap microscope thing I got from China.

[@spazmochad]

@@michaeldranfield7140 That's really useful. I bought an expensive scope but it's still sat in the box. As a hobbyist I just need to have a better view occasionally and just can't face setting it up 😁

[@michaeldranfield7140]

@@spazmochad I really need a better way of magnifying but cant justifie spending a lot of money when I hardly do any repairs now .

[@Solder_it]

Thank you very much! Subscribed

[@andrewofford1533]

Sounds like it built that way, so it fails after a period of time, to make sure you end up buying a new set.....

[@michaeldranfield7140]

yes, others have suggested the same , built in obsolescence .

[@CriticalThinker84]

Hi Michael, comments are off for the fiat 500 cluster video. Which i wanted tk say was really helpful for me. Could you please let me know what part numbers you used for equivalent replacements for the broken Surface mount LEDs. I also have a probkem with the LCD display not showing anything. If you have any info on that too would be great. 😢

[@michaeldranfield7140]

I turned the comments off because I could not find the exact part number of the LED s , I got some replacement ones from RS components but they were not as high as the old ones . I had the LCD display go off on one of my fiat puntos and through youtube found a supplier in Lithuania I think it was .

[@ramirez036]

I have the clicking on my samsung, the on/off light flashes 2x 5 times with a longer pause. I'm gonna follow this troubleshooting and see if I have the same issue.

[@mistergee2k10]

Hi brilliant video, really interesting and informative, what does it mean when a TV powers up but has a dark blue screen? I've 2 tvs like this and want to repair then as they are both smart tvs. Thank you in advance

[@michaeldranfield7140]

if the sets you refer to with the dark blue screen are made by vestel then its the LCD panel that's faulty , take a look at the video I posted just before this one , the Hitachi with no picture as there is a work around to make set the set to produce a picture.

[@mistergee2k10]

@@michaeldranfield7140 great stuff thank you I'll shall have a look now buddy

[@DADEMANA]

tanx u papa

[@michaeldranfield7140]

Many thanks .

[@beto1541]

I have a tv I changed my main board due to it wasn’t reading the controller commands when I swapped it out it was doing the commands on the remote for little while and boom it stopped working could it be the power supply?

[@exittech1282]

nice work

[@michaeldranfield7140]

Many thanks for that

[@campbellmorrison8540]

I don't fix TV's but Ive been fascinated with your series on Samsung as I have one and sooner or later mine will die. However what was completely new to me was the S3050 I'd never heard of such a thing so there's my something learnt today :) Im fighting my way through the datasheet BTS3050EJ from Infinieon but I suspect this is not the device you are talking about as its pin 8 is a ground. Would you mind clarifying the device please