@@ilijadimitriev8148 or one or more LEDs could be shorted causing the overcurrent to trip/pulling down the voltage rail and therefore measuring 0 volts.
I’m guessing it’s the LCD flex cables at the top of the screen. They heat up and expand causing the intermittent contact. Give them a wiggle to see if the lights come back briefly.
@@creeper2671 Your right. I fixed my 50" TV by replacing the backlight led strip. You need to pull each layer of the screen off and will eventually get to the metal frame holding the led backlight strips.
@@Creptex yes. I did nothing like this, but i seen that on a lot of tutorials. They said that there was no imqge but sound, and with a flashlight, you were able to see a little bit of the image.
the ones who failed is never have a try! If he have the right parts he would might get that working again, its uneconomical and not worth it in Australia that why!
7:35 Those fractal dust deposits are most likely due to diffusion limited aggregation (DLA). As succinctly as I can describe DLA: dust moves around in the chassis via Brownian motion (somewhat randomly but influenced by other dust particles and air currents). The initial dust "seeds" naturally get stuck to non-smooth edges (in this case, the injection molding ejector pin indents). Additional dust deposits via both physical impact and dust's own electrostatic charge. Since the shape of the chassis limits the dust motion to effectively a 2D plane, any minuscule bump in the initial seed is more likely to get another piece of dust stuck to it than for the new dust to make it past the bump to the center of the seed clump. As this process repeats, the bumps begin forming into arms. Any tiny bumps on the arms may similarly form additional branching arms. You're more likely to see this inside a TV than a laptop because TVs are passively cooled by convection. A laptop's cooling fans push enough air to disrupt the Brownian motion needed for DLA.
dang, was not expecting to learn that much. you explain that well. perhaps the repelling force from the like charge of the dust particles also makes them spread apart like that? just not enough to become disentangled from each other
I've had similar "fun" with an LG set and I also thought initially that the backlight driver was the culprit (voltage went up for a second on powerup then turned off). However, after some more troubleshooting it turned out some of the LEDs in the strips burned out. Replacing them fixed the backlight issue, so it seems the driver board checks if the backlight is drawing the correct amount of current.
Did this exact repair a couple of months ago, there was no need to mess with the board at all. Out of the top and bottom LED strips, 2 LED's burned out and it made the top and bottom not work, bought replacements and it's working as new. Not saying this might be the case here but since my problem started out the same way as Hugh's one (top illuminated and bottom bit dark) it might be worth to check it.
I had the exact same problem. I replaced the psu unit but gave up after I found out it was the leds. That was too much work and money for a tv that old and cheap :)
Yeah, I also experienced this with a cheap TV from TCL. I took it apart, replaced all the LED strips, and the TV was working again. I did manage to crack the LCD panel taking it apart but part of the image being broken is better than no image at all I guess 😬
Fun fact: The primary smoothing capacitor stores up to 330V (220√2) or in more expensive units featuring APFC, theese go up to 450V (writing this as I watch the video) The fact that you sat the bottom part of the screen go darker, means that the bottom row of the backlight failed, causing more power to flow trough the top part killing it too, you had to replace the backlight strips, or if you wanted to keep the budget low, replace the old strips with a standard 12V led strip and use the external adapter. (you could go searching on the supply for a suitable rail and building a controll circuitry, but that is quite hard to do. I like the chellange, saved a few monitors and TVs this way.) This happens due to bad cooling on the strips or the manufacturer overdriving the LEDs as the part of "planned obsolecence" or just to get the brighter picture for cheap. No output voltage to the strips was caused by the controll chip detecting the overvoltage on the output (due to the strips beeing open) and shutting down. The scrambled picture is caused by the bad solder joint on the controll circuitry. The LCD displays do not wear out, they can only break or develop "LCD screen cancer" (a lot of dead pixels on one spot). New stuff is never as reliable at the old stuff (newer things are junk).
I always hear the sentiment that "old stuff is much more reliable than new stuff" does that not sound like survivorship bias? I can imagine that there is a bunch of old tech that does not work and the old tech that is "good" is usually because it is one of a few products that survive.
@@aMMMMungus I'd say yes and no. If you are talking about more mechanical appliances, the stuff from 50s until early 80s are more durable, simply because the materials used, QC, not existing an amount of white brands flooding the market, compared to nowadays. You can still get very durable appliances, but you would have to go for professional/commercial level to have the same durability. Also, the cost, a blender back in those days, for example, was way more expensive than today's (inflation adjusted). Now, if we are talking about electronic goods, it's definitely more streamlined and reliable now a days, to a certain extent, but with the cost of not being able to repair it so easily. Now in European Union, brands will have to provide and design more repairable products. I did a work study at university about the planned obsolescence, many of the products displayed by other groups had a good that failed,due to a really cheap nylon or metal parts. Meanwhile, we did a study on a by then 25 year old mixer that was still working perfectly, and couldn't fault any of its components due to the quality of the build and parts. And the funny thing was it filled with old flour and still worked perfectly fine.
@@aMMMMungus No. I mean sure, some of what you say is correct, but there has been a very noticeable drop in the quality of manufacture across the board over the last 30 years. Essentially, everything now is built to a price, and often planned obsolescence is a factor.
The micro soldering shots are indeed super satisfying 😎 Also, there are a few Sony tvs in our local 24 hour gym that have literally been on non-stop since late 2009 and they’re still going strong.
The TV world has changed a lot, sadly. 50-70 years ago, TVs were very expensive, and everyone was fixing them. There was a HUGE TV repair market (Especially when they still used vacuum tubes). Up until around 2005-2010 (CRT, most Plasma and many LCD) most TVs were very well documented. Service Manuals were available for anyone willing to pay, even big 1000 page books with schematic collections. Most TV repairmen diagnosed and fixed down to component level. However starting with the 2010s this changed a lot. Instead of Plasmas and early LCDs having sometimes 5 or more boards, now they ALWAYS just contain 2 or 3 (PSU, CPU/Inputs, sometimes TCON). TV repairmen just changed those. However even this is not done often anymore. TVs are not anymore a high tech unit, they became very cheap, and most of the time the cost of a replacement board is more expensive then buying a complete new set. Just think of what would happen if any TV nowadays would cost 2000$ or more - the repair business would probably flourish again. That is also most likely why it still is active in india - people cant afford new TVs, so its worth for them to repair what they have.
He legitimately sounds very mature and professional. When I was 20 I was a rebellious piece of shit. Genuinely impressed with this guy. He's already gone places, but I see more places he'll be going.
Like many others say, you should replace the backlight strips. Fixed my LG this way. It had the same issues like the tv you're shown here. Some of the LEDs failed. If too many of them fail the tv senses it and doesn't turn on the backlit to not burn it up. My LG actually had marks of internal fire. Luckily this safety measure is in place. Replaced all strips and runs fine for two years now.
Very likely the LED strips. You can buy replacements or make your own using those RGB strips everyone puts on their desks etc but you just need the white one. Nice to see you branching out though.
Most likely, my dad does LED TV repair for living, most of the time replacing the LED strips fixes the problem. But you need to disassemble the screen assembly to replace the LED strip, so you gotta be careful handling it.
@@mindofvirtuoso3358 you can either mod it or replace all the SMD LEDs on the LED strips that comes original with the TV. Replace all with identic LEDs for even white light across the screen
Hey! Huge thumbs up for your efforts to make electronics back to work again. This is vivek from India and yes we Indians do repair our electronics whether it is small or very costly. I request you to please keep trying out new projects as it makes us more engaging to you.
5:50 after 5 years in SMT and through hole assembly, I can explain the glue under the chip. With this being a singe layer board (when produced in these quantities, single layer saves a lot of money compared to dual layer), all the SMT components are attached with a heat setting glue to hold them to the board. After all the SMT components are glued on the boards go to through hole/hand assemble, after all the through-hole (THT) parts are in place, the board is wave soldered with a solder bath, so ALL the SMT parts get washed over with solder which gives them their electrical connection. They have to be glued before wave soldering as, if they were reflow soldered, when the solder bath operation happens, they would literally be washed off the under side of the board.
A shame you couldn’t get it working but serious respect to you my friend! 20 years old. You seem way older and the fact you’ve learnt these skills shows how far I’m this particular line of work you’ve got yet to go. Kudos to your channel and commiserations for your parents TV
This happened to me with my 43” 4k tcl, I bought new backlight strips and a main board, tried the easily replaceable main board and it wasn’t that, so I replaced the backlight strips, very carefully, and it worked, make sure you keep track of the backlight diffusion panel order, I had to take my tv back apart and reorder them. I spent $30. I made sure to get the parts from a place that had easy returns, I always do this, it was very helpful when I fixed my fridge and dryer as well, I returned all the boards and fans I didn’t need.
This was a departure and an interesting video. I myself have a 32 inch LG TV that I have connected to my PC, mostly because I repair PCs from home and this particular TV has 3 HDMI inputs as well as a VGA input, so I can run multiple devices at once and use it to test out the functionality of older devices at the same time. Back when I lived in South Africa, we had a Sony TV from the late 1990s which was a CRT, we stopped using it in 2012 or so and replaced it with an LCD TV when high definition channels were becoming more available. Sony have always made really solid TVs.
Recently I had the same issue with an older LED TV, turned out that the entire backlight was just a series of LEDs, took only one dead one to make the whole thing go dark.
I had a similar issue with a Samsung TV my family bought around 2014 - 2015 in which during 2021 a year ago the backlight and power board were not functioning as intended but I originally thought it was only the backlight. I then ordered the backlight and replaced it but nothing seemed to have worked. Then I replaced the power board and it then worked and the backlight was brighter than before.
Hey there, love the video. Idk if you'll ever see this comment but I thought I'd leave it here. I worked on LCD/LED TVs for about 3 years (along side computers and phones and such) and have seen this type of issue a lot. Given that half of the backlight was out before they all went out it's possible that the LED strips under the panel are bad. They're not very difficult to replace, it's a procedure I did often, and they're not too expensive either (depending on the brand/model), just a time consuming repair as you practically have to disassemble the entire TV. The LED strips typically contain contact pads that you can inject voltage into to test the bulbs and see which ones went out. A lot of the time, if one LED goes out, it'll take out all the LEDs on it's strip. You can also replace individual LEDs instead of the whole strip assuming you can find them. Maybe for next time you get a TV that has these types of issues lol
Great video! I believe the weird dust patterns on the back of the TV resemble a Lichtenberg figure, it tends to happen on high tension circuits when the capacitor's insulation goes bad.
8:44 Haha, as you were talking about how dangerous CRT repairs are, I was reminded of ours where we had AV output ports installed on it which originally just came with a COAXIAL out. Because of him, we could use it for another 10 years or so!(1991-2013) He would also repair it when it would break. He was our cable guy!
I have a 24” Insignia tv, I’ve had it since 2011 and it still works today. Only reason why I still use it is because it has multiple HDMI ports/ AV and Component. Yes newer tvs have multiple hdmi ports but they usually don’t have av and component ports anymore and I still use them on my current tv.
You aren't wrong about TV repair being so uncommon in the west! My brother and I both brought Sony PVMs in the UK and found a guy with a lot of CRT expereince to get them re-capped...however the repair guy is, so I'm told, one of only 2 English speaking people who knows how to fix them.
Awesome hugh! TV repair shops are a common thing here in India. We like to keep our devices running as long as possible and discard it only when repair is not a viable option 😅
Here in Brazil tv repair shops are very common too, 4K tvs here are expensive just to trow it and buy a new one. We try to fix it, sometimes it is an easy fix
I had the same TV for repair a few weeks ago. It also had no picture. TV was under brand Kruger&Matz (model KM0248). It had broken 3 or 4 LEDs out of 80. Those LEDs are in straps and are connected to two connectors. If even one LED is open or shorted, then one part of the screen (left or right) will not work. In your case, you have problem on both sides. PS. Be very careful with assembling the display, it is very easy to break it.
It will be better if they sold dumb but relaible tvs and just buy a tv stick for it. My Sony LCD TV has now almost 9 years, it is dumb and i just run a tv stick. I have had zero problems so far. Great video Hugh, keep them coming. Every day i care more about reparability!
I have a old (2008-2009ish) Sony Bravia 32 inch. Got it from a closing retail store. It was on for almost all of its life yet it still goes strong with excellent picture quality and no burn-in!
The power suppplies in these sets almost never die before the LCD panel itself which renders it as a junk. The culprit here are the Backlight LED Strips, even if one or two of them die the whole circuit will break and not work due to the imbalance of Voltages.
Thats the issue when you dont have the necessary materials of knowledge to troubleshoot something. Its hard, even with Bsc in Electronics. Experience comes with personal training and also having the right job to learn. You are doing great, sometimes you need donor parts to repair. Pros may have a board, to test the panel. Or even have similar panels (in case of known brands). But companies want their stuff not to get fixxed easily and the right to repair is our only option. Ps My monitor had problems switching off, but only searching for 10 mins, I found the problem 2 capacitors and its like new, I have repaired an psu for a pc and its still works.
Yes, I have two TV sets from Sony at my home, one from 2009 and another from 2013, and they're still running much better than most random brand TVs (actually all these cheap TVs are most likely made in the same factory, by the same company but under different brands, in China).
I'm still using a TV I bought from eBay before COVID-19 shut half the country down. I'm talking about the United States. It has a few minor blemishes on the screen, but my 40" Bravia is like a tank. I'd love to replace it, but since it still works I can't see it as something necessary. So yeah, I kinda get your point about older TV's. Keeping some of them working can be frustrating.
I am from India..and coincidencely a tv repair technician ...too i can give you a cheap. idea to this problem..In this case to reduce cose we use 'Universal backlight driver' cost around 3 to 4 us dollars in India.. obviously made in china..the connections are simple..if that didnt work..then you have to open the panel and check the led strips behind it...Ok do it just for fun. I always appreciate your videos..
Nice video. I really appreciate the honesty with which you also show content like this. It is not always possible to fix everything and, sometimes, it is not even economically sensible to do so. The motherboard you showed was definitely not the best made and your parents sure love the new Sony TV.
One of led strips has died (indicated by dimming of lower sode of the screen) I believe that if circut isn't completed, You won't see any voltage on backlight power. I've fixed few TV's with the same behaviour. Also you can test led's in the strip with multimiter, just put into continuity and check the led swapping the leads between it"s pads, if it glows it is good, after finding the dead led (maybe more than one) you can jump it with the wire without replacing the strip, but it will increase the load on the rest of leds, but as a test you can do it. And be careful with an LCD itself, it is a stront as a potato chip.
I do think you should try to look for the LED backlight as I suspect that it has blown. That was the main culprit of our 32" LG Smart TV and replacing it fixed the issue.
Cool. My old LCD Westinghouse tv was still working when I gave it to my friends parents. It has outlive two remotes. I bought a exact replacement the first time( my cat tried to eat the buttons on the first one.), the second I was cheap and bought a universal remote. Was still working when I last asked about it. That tv survived the same cat knocking it over. It only popped the frame off a bit on one corner. That was a tought ass tv.
Check the backlight LED strips. The PSU probably just noticed there is something wrong wit the LED strips and cut the voltage. If you don't find suitable LED strips online, measure the LEDs and you might be able to somewhat replace them with common LED chips.
i replaced a power supply in a LG plasma tv about 8 years ago. still using the TV today. beautiful colors on that plasma. The bad part is it doesn't remember any of your settings and always reverts back to the settings it had on the day it got fried.
This reminds me of that one Vizio TV that I fixed up just over two years ago (and it's still working to this day) Ever since then, I've came across at least 3 more TVs that were being discarded that I wanted to try fixing, one being a 60-inch LG 4K TV if I recall correctly, but all of them had broken LCD panels, essentially making them worthless due to the panel's price (unless I wanted a fancy faux-sunlight lamp with them) Modern TVs have always been weird to me; some are cheap, some are expensive, some basic parts are cheap, and the most fragile parts are expensive, they're always awkward to resell, and problematic to dispose of if something goes wrong
The TV repair shops are a dying breed in India too. A few months ago my Toshiba TV gave me a blank look. Brought in the service guy and in 10 minutes he changed one board ( of the two inside) and voila! The TV blinked open its heart! Thankfully it was under warranty and I didn’t have to pay for anything. I was told the cost would have been the price of half a TV!
My boys 6 and 9 love to see your videos. Today they were more than happy to see your face in the video. Thanks for mentioning repair shops in India, My country. Huge love and respect from INDIA.
Have you tried the backlight leds? If a single led blows, the psu will detect that and will turn itself off. Or a low capacity(worn out) capacitor can effect this measurement too.
Yes. I'm over the moon you did something other than phones. Don't get me wrong you're brilliant at repairing phones it's just good to see something different. Was an interesting video even tho it wasn't a fix.
I had similar problem with a TV friend brought to me for repairs, different brand though. Turns out the caps on the low voltage side of the power board had gone off. Six euros in parts and half an hour of work and the TV was fixed. Those caps on low voltage side are a common failure mode on a lot of LCD displays/TVs.
Hugh, it's very refreshing to watch your videos compared to some of the other crap out there. Based on the fact you are only 20, your level of intelligence, grammar, etc. Are very impressive! Keep up the good work!
3:25 If you have a J or knife edge solder tip, you should try one of them for reflowing chips. They move a bit more smoothly across the pins letting you tackle each side with 1 nice drag.
Yup, it’s the backlight LEDs, replace them or check the strip one LED at a time, last one I fixed it was just a loose connection on one of the strips. Usually if any LEDs are open or shorted, the PSU will just shut down, try removing one of the backlight connectors from the PSU, that might show which strip is faulty, it looks like there are 2 LED circuits in this TV.
i had teh same fault on a 50" Goodmans 4K set, the power supply was fine, it ended up being one bad LED that tripped the protection circuit preventing the backlight from starting.. the only solution was to identify the bad strip and installing a replacement but there is only one problem, you have to completely strip the LCD panel down and handling a large LCD panel is harrowing at best as one slip and the whole thing is ruined and after 3 backlight repairs mine finally died for good after cracking the LCD trying to mount the bezel that holds it all together...
The backlight issue, sometimes repairs here in Indonesia, they just bypass or modify the problematic area but with potential drawback of no brightness control.
Hey Hugh I had a similar issue with 32 inch Led TV and as the TV was under warranty the display was changed and it has been working fine since so it's not a board problem it's the Display which is faulty maybe the back lit Led's are dead.
Hi Hugh, your backlights are physically fried. they are shorted out which is putting the backlight circuit into protection mode. There may also be other sources of backlight voltage (around 40-60V) you can probably jack from and wire in. Give it a go and see if you can fix it. Take the lcd panel off and replace the faulty leds. each led is 3v, run a couple 9v batteries in series to test each strip.
Shout out back from India, Repair industry is under stress in India too, When I was kid 'Easy To Repair' was the sales pitch in the electronics showroom with several homegrown and Japanese electronics brands. Now the market is flooded with electronics made to be e-waste in 3 years (or) less from (you know where). Which is dangerous as we have to not only deal with our e-waste, But since the neighbor to the North have banned waste dumping; India has become a destination to dump world's e-waste too. Then again, Due to economic reasons you can still find a TV repair shop like you showed in the country; Mostly in rural and tier3 cities.
Happend to one of my old TV's. I Just replaced the LED strips that located underneath the panel itself and it worked. I don't know what cuased the flickering but the Led replacement should most likely solve the image brightness
since you have picture with no backlight , check the LED strips underneath the LCD, usually the LEDs on the strip are connected in series, if on or more LEDs blown, they all turn off.
I’ve had similar issues with a Samsung TV, the culprit were the connections between the halves of the Backlight Strips. Since the normal connector didn’t work I just soldered some cables in the connections and it fixed it. But be aware with the LCD, it breaks easily :)
Oh my gosh, you are only 20 years old?!? You are much more skilled that I am, and I am 18, it is amazing that you probably were my age when you did most of the videos that I look up to
change the led striped for those normal led stripes with it's own power supply, so when the lcd dies you can take the power supply back and use it again
You don't need to be an engineering student.... You really proved age dosen't matter you're only 20 years but more than an engineer, great job Hugh! Love from India Brother!!!! 💜💜💜💜💜
im absolutely baffled by the fact that youre a mere 2 years older than i am at only 20. i honestly thought you would be a lot older. its genuinely amazing what youve accomplished at such a young age.
My father is a TV repair technician (25+year's of experience). He fixes these so called e-waste without the fancy tech ( uses a head mounted lense).. But nowadays he also gets fed-up as things have become very hard to repair. According to him CRT TVs were the best.
my sony ex72 had partial backlight dimming issue after 2 years and luckily it was still under warranty so they swapped the whole panel with a new one. thankfully after 15 years or so it's still working fine.
The LED strings could be bad or the logic board of the area that powers the display, usually that is what fails on those cheap Tvs. Disassemble the display panel and test the components there.
I don't know much about TVs and repairs, but from what I watched, did you check if LEDs are working. Because maybe low voltage is due to LEDs not drawing power and failsafe engaging. I am not sure if I will put this correctly but I think on cheaper TVs, LEDs are connected in a way, where one dead LED can cause whole strip to fail, if this makes sense, not sure if it is called parallel or whatever. But I did watch few repair videos on other channels a while ago. And it feels like this would make sense. Sorry, if I confused anything or put it wrongly, as I said, totally not an expert, but it feels like something in those lines could be happening. Also can't really remember how it was tested.
Would recommend you check in to SOIC desoldering tips for bigger IC removals, or basically those that you can manage to see with your eyes. Less use of the heat gun then, less burn.
I've been wanting to up-size my living room set for a couple of years, but my very old 32" Sony Bravia still works so well I just can't justify it yet!
I have the X85j that your parents bought as well. Fantastic tv with great image quality and amazing smoothness. Got mine as a massive discount ( friend of mine Boss at sony CHCH new zealand and got the tv down from $1799 to $1249 for me )
I wonder if its actually just the Backlight LED burnt out itself which is actually way more common Especially with the symptoms you explain before where the bottom part is darker
