EEVblog
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- เผยแพร่เมื่อ 18 ส.ค. 2015
- Dave & David2 have another go at repairing the dumpster dive 46" Samsung LCD TV.
This time a further teardown checking out the LCD panel TAB connections, and then reflowing the T-CON Timing Control board.
You know how it ends. If you don't like the lack of a happy ending, don't watch.
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Hello Dave, I've been watching your channel for about 2 years and you are the reason I'm somewhat interested in electronics. I've got no idea what you say actually means but I feel like I'm learning
RandomVideos It's true watching Dave talk about electronics and explaining things makes it so much easier to understand electronics. When I started watching Dave's videos for the first time I didn't even know what those round pads on the pcb's were. turns out there Fiducials. And well thats a thing I'll never forget now.
RandomVideos Glad to hear, thanks! Similar to when I was reading electronics magazines when I was 8. I didn't know what most of it meant, but then years later it all clicked and WHAM came all the knowledge in a flood.
Yeah, he is a good engineer and explains things well but his repair videos always seem to end up making me cringe! :) Usually accompanied by a few [facepalm]s and shouting back at the screen in anguish... :)
Keep up the good work, though, Dave!
+EEVblog Just like me you are Dave! I had boxes and boxes of pulled apart stuff under my bed when I was younger, I only realize now what I actually had and what I could've made with it :/ Never too late to get back into it :)
I love these attempt to repair videos. Like a good detective story it keeps you wondering. I hope you'll continue your investigations and figure this thing out!!
Loving these repair/diagnostics videos, as a tight ass dumpster diver these videos only fuel my passion to fix what others would gladly just bin.
Thanks Dave(s)
I love these repair videos. I'm learning so much form all this.
These are very good vBlogs in this channel. Thanks Dave.
The TV manufacturers won't like it if you find a bypass for their "Built in obsolescence" lol..
A very interesting project though. 👍🏼
Green Silver It's always funny when it ends up being 3 dollars worth of capacitors. I think they've caught on that people are fixing these issues easily, so they've stepped it up to corrupting something or just having the chips shit themselves after a while.
It is easy to make a chip die prematurely. In the NMOS process, a little too much boron in the glass passivation layers will slowly cause the boron to slowly diffuse into the chip substrate, killing the chip. This was the problem MOS Technologies (Commodore Business Machines) had with the chips used in the C64. As they heated up (they ran hot) over time that made them diffuse faster and faster.
I just love this kind a consumer electronics diagnostic videos. Keep them coming. :)
Love these videos Dave, Just getting into the electronics field and love to see how these lcd panels function.
The problem is the LCD panel, this is a very common problem for Samsung TVs. If you disconnect one ribbon cable from the Tconn to the panel the problem might go away (only half the picture will show) and you will know the side that is causing the problem. You can also try some freeze spray on the COFs to see how it reacts.
Did this TV ever get fixed?
Problems like this are so interesting. Keen for Part 3!
Love this fault finding problem, yes get the Scope out.
This has been fascinating Dave.
What a result if you narrow the fault, even if you can't repair it, great experience.
The fault does't appear straight away, suggesting a heat fault, maybe it is with the tecon board after all.
If the heat fault is in that board, you may need another ASIC.
I like this kind of videos, its got like an investigation/ mystery theme to it. so exciting. Reminds me of the Yamaha Surround Sound Receiver tear down/ Repair. love it.
Dave, from my experience with my TV, it is indeed the T-con board. You realized that the lines are exactly where the letters of the menu are, as if the menu "caused" the problem. If you put a digital image to it, the lines will probably disappear after some minutes and the image will be totally clear until you bring up the menu again or if you try to watch anything analog and the image will probably get even worse then. I'm telling you this, because that was exactly the symptoms of my set. Replacing the T-con solved completely the problem here.
According to what I read, the chip the causes the problem is a small squared one with the code AS15-G (at least in my set)
The fade-in and shadowing says "floating input somewhere" to me
mikeselectricstuff It seems doubtful that anything is addressed by column in a way that would break things across the whole column before *and* after the text except for something related directly to the panel.
I'm somewhat familiar with how this failure mode might occur with OLED panels, but I'm not that familiar with LED panels. With OLED panels, you need to reset each element to a certain voltage before writing a new scanline. It would seem here that something about each vertical column isn't getting reset between scanlines and some voltage or charge is building up across the whole column. And it's panel wide.
mikeselectricstuff That's what I was going to check with the scope if I get around to it.
I had a similar issue with a tea damaged LCD panel from an iPhone 4, but it was more in the opposite order. The panel would start up fuzzy and eventually clear up after being on for ~10 minutes. Some characters made bigger lines to be displayed as well. It has 3 chips on the panel(chip-on-glass?); two drivers apparently for each side of the long edge, and the wide chip tcon/short edge driver. The LVDS bus is fine and then phone has no issues with a new screen.
Definitely something floating...
Gustavo Ferlizi Are you British? Surely you gotta be British if you managed to damage an LCD panel with tea.
All the vertical lines, line up exactly with the OSD text, so its looking like it is possibly an issue driving the framebuffer RAM's, I've seen the same style of issue on a much lower tech LED sign display, caused by a decoder with leaky outputs not fully turning off after drawing a pixel, so you ended up with faint trails on the next lines
can you explain for me a little more please ?
Dwwd
Dwwdd
I would bet on memory problem with some of the cells. I would:
1. Install custom linux image from: www.samygo.tv/
2. run memcheck on PCU board
3. swap/change memory modules on video board
Surely it's 1920xRGB=5760 columns?
mikeselectricstuff Not the first time Dave forgot pixels have rgb elements.
mikeselectricstuff Err, yeah, Doh.
+Gone Tomorrow I would assume mobile phones have a lot more on glass logic to get passed that.
***** but its not only theirs 3 color for each pixel but you also have two lines correspond to each subpixel and a transistor in the corner.
EEVblog I may sound like an amater , but does the smaller BGA on TCON board looks like it's gone...? Looks like it's burned out... Warped... Shines more than the big one?
I used to heat the boards to the oold CRT TVs on the gas stove. Once I heard cracking, I would drop the boare, component side down, and all of the components would fall out. That is how I would quickly collect boxes of components for fee. Great video.
Frank
Maybe interesting: hoe about doing a reverse repair! Introduce an error and look at the effect. Two examples 1) Cut a trace (repairable) on a FR4 based board leading to a flex cable, goal discover what a bad solder joint would introduce. 2) introduce a "stuck at" 1 or 0 error on memory databus.
Danny Bokma
Yeah, I like the idea. It could have more educational value than a repair, and maybe more spectacular results.
nativewinner Spectacularly smoky and then the fire system kicks in :)
From my experience with the same problem on LG 42" LCD TV (exactly the same manifestations), hotbar connections were the problem. That sticky conductive transparent tape (forgot the name) that bonds flatflex conductors from LCD glass to that upper board was not conducting any more. With blowing hot air from hot air gun, and more importantly putting rubber bars that mechanically pressed the connections, TV was again having good picture. That worked for about the year and then started going bad again. Problem with my TV were old CFL lamps that were getting pretty hot (glowing with more red color), and whole tv screen got hot and those contacts to the flatflex were ruined. After that 1 year of extra life, and 6 years form TV, i just bought new one...
hook up a video signal to it and watch it clear up after the menu text dissappear.
I have to agree, hook a Pi up to it, and check if it's just the menus, or full video problems
dreamfox32 Now that could be useful in isolating the problem. If it completely clears, the "character generator" could have a fault, or the connection from it to the next stage in the video processing. I imagine it's not a separate chip but integrated onto one of those custom jobs on the "processor board" as we're calling it. If I had to guess I would say those chips are not going to be available and full board replacement would be required.
dreamfox32 Did you miss the test image in the previous video?
hendik hendrik Wasn't the image test was generated by the processor board, and not by a completely external source?
dreamfox32 How would that repair the fault?
i love it when we are in like flynn!
Ten points for keeping it up. I'm sure you guys are closing in on whatever the problem is. Sorry I can't help to diagnose but the character issue seems important. It's odd that stuff is being drawn in placed where the letters never really go. The center bit moves up and down a bit but the 'PC' string pretty much stays in place. Something's not turning off when it should...Good luck guys. Hope you find it.
Another cool and very interesting video!
Keep going. It is very interesting watching you trouble shooting. I am at the stage where I want yo to find the fault and be able to fix it. That would be great. It is always a pleasure to watch someone who would try to fix something rather than just throw it away. Good on ya.
The lines appearing only where the characters are looks like a RAM addressing issue to me, like a floating / stuck address line. Since it fades, it's probably floating, so you get an average over time of white and black (text and background) on the whole column. That also explains why the lines have colors close to the text color and the striped pattern (the regular spacing of thin black lines in the red columns)
What’s the fix
this would be great to watch LIVE! :D
You didn't put any pressure on the flat flex where it's bonded to the LCD glass, which was the location of this issue on the 2008 Samsung I had. Notice how the lines follow bright areas in the picture at any row. Maybe one of the return lines for the row drivers has lifted, and every pixel in the row slowly floats high if one is high?
keep up the good work Dave and David for my two peneth I would try and use your thermal camera and see what heats up at the same time your lines appear don't think you would have found it with the freezer spray as when you change the menu it takes a while for the old lines to disapear.... I have found a couple of faults that way before...
EEVblog Dave, this whole stuff can be because of low gate open voltage, there is a dc-dc converter on tcon board somewhere which drives gates, check voltages
One Hint for the problem not being linked with a faulty panel might be that all the vertical lines appearing on the display are somehow bonded with the characters displayed! Red collumn -> orange "PC" letters, cluster of lines in the middle -> "Check signal cable." and the one in between -> the ":" in the time (?).
The problem seems to be more evident with antialiased fonts drawn by osd software lib (you have the issue near the curved lines and not on the horz and vert lines that are instead perfectly row/column aligned), this suggest a timing problem with partially lighted leds...
I think you should input some video test signal from a pc software generated image and see if we have changes with full red, full green, full blue, 33% rgb, and so on...
It would be great if you had a service manual showing testing points. A real time saver.
seems like it could have something to do with a chip heating up, just based on the way it fades in. you could try blowing hot air on different chips while it runs, or look for a particularly hot chip with the thermal camera.
All I can do is wish you both good luck on this restoration attempt.
It really would be great to you beat the gremlins spoiling an otherwise beautiful TV.
Really good videos, i was wishing that you succeed, always want to learn more, i felt as if i where there with you, don't like to be beaten. please post more on this one.
Let's see:
1. The lcd panel cables are good, if the lines would appear instantly after powering the TV on than flex cables would be faulty
2. the panel is not damaged that is a fact, a damaged panel would not have straight lines but bleeding colours
3. power supply is good
4. Image processoring is working because there is video output to the panel
5. The issue is on the video output source
So if you put all this together you will se it is related to the T-con, something on the board is damaged because when it is heating up the lines appear slowely (vertical lines) these other horizontal lines are most likely because of some small voltage disruptions on the T-con. I can not say what exactly is damaged on the T-con but you can try and look deeper in to what could be wrong on the T-con's circuit, if the chip is damaged than it is best to buy a whole new board
Here is one, I don't know what model do you have de.aliexpress.com/store/product/LN46B650-or-LED-UN46B7000-BOARD-2009FA7M4C4LV0-9/710086_614153320.html?storeId=710086
Been thinking about this one, leaning towards the signal gen for the OSD.
My bet is framebuffer memory on the main processing board - some rows in memory flip bits, some stay flipped, some decay - this is what happens with videocards. So possibly a memory line doesn't get a refresh signal or something like that... And because it does some postprocessing on the faulty data, it can produce different artifacts depending on when and how the bits flip.
If you look closely, lines do align with "P C" (the red ones) with check cable, and with time dots. Looks like some sort of filter accumulates values or something, definitely something with the scaler/frame buffer or something like that.
I have the same exact problem on a 42" Toshiba from about the same time period. Vertical lines appear in columns containing text, and horizontal "missing" lines are constantly there. It seems to come and go over time; I've been able to use the TV for the past few months without too many problems, but sometimes it just gets in a bad mood or something and the lines cover everything up.
I have repaired similar TV's and it was an issue with the ribbon cables coming off the lcd not making good contact in the connector. I would use packaging tape to make the cable a bit thicker for the fix.
Can you use the oscilloscope to check the io for the pixel column that's having the problem. You can look online for what voltage you need for what colour and see if you can see anything unusual then trace it back to the chip on flex and then back to the board etc. Or see if you can a service manual/schematic. Great video.
Lower the brightness level and color intensity and when the menu text dissappear it goes to normal viewing
dreamfox32 Well, it _might_ be reasonably tolerable, but even if the image produced is flawless, I think that would be to miss the point: to make an interesting electronics repair (attempt) video. I don't think Dave is hurting for TVs.
If that was mine I would probably just leave it at the appliance recycling place, and buy a new and better TV. They are so cheap now that they're practically disposable. That said, my 40" Sony LCD from 2007 is running like a champ. It's 10cm thick, but I'm not looking at the edge of the damn thing. :)
If you look, the lines only appear where the text is, I'm guessing T-con for sure.
Have they tried actually feeding a signal in over HDMI or VGA?
This is why TV repair is best left to specialists who have the test equipment. For an electronics engineer wanting to make spare money in their time, it's just not economical enough, but perfectly OK for a blogger on TH-cam if it means a large audience.
There have been up to now 10.000 people including Dave and David learning and being entertained from this dumpster-dive TV. Not sure if there's a way to get more bang for the (zero) bucks. ;-)
The Horizontal lines appear to be split between the two sides of the panel(like, even rows on the left and odd rows on the right) and the left horizontal lines "driver" (when the panel is the correct side up) is completely gone (hence no display). But since the vertical "fault" lines appear even on the side with "no" horizontal drive that could be some indicator that the fault originates on the main board that generates the signals for the rest of the components (it skips processing half the rows except where there is an error or "overflow" that produces the vertical lines). Hope this was helpful...
Im keen too see if you do ever get this going, it would be very satisfying if you do
Just to echo another comment or two on here - Mike said floating input, does look that way. Someone else mentioned reflowing processor board and considering OSD text having effect I do agree it's probably the processor board. Something perhaps needs reflow on there.
GadgetUK164 There is also a very plausible theory about the gamma buffer or other analog drive system at fault.
+EEVblog Interesting. When are you going back to it to find out?
Holy cow, you actually called him David for a change - after a dozen times saying he doesn't like being called Dave!
A bench with a clear top and a mirror underneath might be handy for doing this job solo. Our Sony has the exact same failure, it happens with on screen text even on the broadcast picture, putting the TV on a radio station clears the issue temporarily.
Some of these ghosting effects remind me of what some LCD displays do when you turn them off. In particular, when I switch off my old Game Boy Advance, every few rows appear to persist for a bit.
My hypothesis is that for some reason, the pixels are having a hard time turning off. When a row is being driven, the voltage for a particular column could leak through to other rows, and without a strong turn-off force, this leakage gradually causes pixels to turn on.
One possibility is that if a negative voltage rail is used to turn off pixels, then it's possible that rail isn't making it to the TCON board. Thou shalt check voltages on the TCON board. ;)
I love this guessing theory, I cant wait to see fixed and see what was the problem
+Light Man Yes,
Don't batterise, analyse!
I think I would try to generate some test patterns from PC/HDMI like a single white line (h and v), half of image white etc. I would focus on a horizontal bar of white lines (5-30 lines). They should make the ghosts appear. Probing the signals should suggest at which stage the ghosts come in or where h lines disappear. Using smart display patterns you can make the signals look nice and predictable and easy to recognize when they are wrong.
The lines match up perfectly with what is on the screen, note the PC, : and e. I suspect it will happen on any part of the screen where it aligns with graphics. Could be an issue with the OSD alone. Maybe bad display RAM?
Those blippy pixels right at the bottom (especially at the bottom of the red lines) are quite interesting...
You could try hitting the actual panel with freeze spray, maybe there's a problem with the transistors in the panel at the bottom of the display.
nice traying to save the LCD TV nice video 👍
without having watched the first video, or having the time right now, I'm wondering if this could still be a thermally caused issue. If it was, applying heat or cold to various components would be helpful to find the problem.
I've seen slightly cracked LCDs do this kind of thing. At the edges or corners, or when someone's spilled or cleaned things with the wrong chemicals, eats the metallic traces on/in the LCD itself. Can create high resistance connections, so the LCD itself 'charges up'. The common aspect, though was always a toast LCD, I'm afraid.
Good luck, keep up the cool videos. Stu.
it is shockingly impressive the level of futuristic detail and tech applied into the flat screen.... I tend to think that if such effort was applied into... say fixing the environmental problems... like perhaps deforestation.... then there would not be any problem
I'm that way myself; I can become obsessed with making something work, far beyond any practical accounting of time-spent vs. benefit derived
its funny to see the no signal and input information move up and down, normally only happens on plasmas to prevent burning, but lcds dont burn pictures so im suprised to see it
try your thermal camera on the back, see what warms up, freeze that, as it related to text, how about a video signal input? please try that with no generated text on
In the event of a suspect main ASIC or memory, feed it a video signal (VGA/HDMI) and try to change the resolution. If you have a memory error the patters will move as the picture is placed differently in RAM.
on tcon board level it will always fit exectly the same way in memory.
Yes, as it's behind the scaler board. If it was a memory error i wouldn't appear slowly like that, but be there from the beginning.
Hi Dave, did you ever get this thing figured out? I have the same tv with a similar fault. I was going to buy a 2nd hand T-Con board on ebay and take a punt....but don't know if I will now!
Cheers from Brisvegas
Check the top strip with the IC inside the one on top left is usually faulty just apply pressure on the flexible and it should work!!! i usually use a thermal pad for the IC to mold inside of it en ensure a good contact then you close it and make sure there is enough pressure to hold the contact
The vertical issue was all over the test image as well? Perhaps not specific to ASCII characters rather to intensity?
You have tried it with an external source, it's not just a problem with the OSD?
This trouble shooting is great!!!!! Find it very interesting. Hope you get to find a fix for it though.
hey . have you tried just plugging an input in and see if it works ?? the lines don't se to be affecting the graphics,just the ASCII .
As you have problems on both sides of the split it's probably on the TCON that the problem lies in, as the likelyhood of both sides of the panel TAB bonds going bad at the same time is pretty low. As the problem looks "analog" the scaler board (what you call the main board) is out of the question. A lot of "analog" stuff goes on in the TCON.
Good thing you mentioned that, just like Dave 2
Danny Bokma Exactly.
Danny Bokma Is there anything wrong by getting a second opinion? I have real experience repairing TV's, which Dave or Dave2 does not seem to have.
you had the same explanation, and of course there's nothing wrong in that.
***** Yes, that's the conclusion we came to. That's why I then reflowed the T-CON board.
I am getting the same issue with water damaged cell phone - it draws lines where are some contrast items. In my case i was thinking that the water+impurities are connecting whole lines together - so if anything in the line light us it affects the other pixels.
Reflow all the boards, hack all the things, drink all the beer :)
EEVblog Check those Sam Young filter caps on the power supply board using your ESR meter! I don't see that you did that in either video. I know you have no reason to think they're bad based on ripple and visual diagnosis. BUT - I have a very similar vintage Samsung LCD TV (2009, 55", high end) I'm working on, that also has multiple Sam Young filter caps on a very similar board. One of them was visibly bulged, but even the ones that weren't in the same value (25V 1000uF) had questionable/high ESR values.
The TV I'm working on has the same exact symptoms.
I'm waiting for the replacement caps to arrive, but given the nature of the failure (it worsened with time according to the owner, used to go away on it's own, and it's temperature related) etc, and the fact that one had visibly failed - I'm confident that this is what's wrong.
+Protonus And? Did you fix it?
The Kaiser Sort of! The caps were certainly bad. 1 in that value was visibly bulged, one read a high ESR, the other 2 I replaced anyways. But it didn't fix the picture issue, just make it stop changing with temperature.
So I found that one of the ribbon cables, going between the actual panel and the driver boards at the top of the display, was faulty. If you apply a bunch of pressure to the cable itself, to push it up against the metal frame of the TV, right where that tiny "chip on ribbon" cable is on the short cable, it would restore the picture to about 95% perfect. All the vertical lines and bars, and color bleeding go away. Most of the horizontal lines go away too. The one that was bad is the left most cable for this particular TV. I hot glued the small/bottom end of a small (3/16" thick?) rubber peel&stick "foot" (like you'd put on the bottom of electronics or a speaker) to that spot on the cable. Now when you screw the front metal bezel down, the area of that bezel that's supposed to push on those cables, pushes much harder, and the picture is nearly perfect.
There remains though, some horizontal lines, at fixed 1" intervals though, that stretch across the display. They are mostly on the right half of the display, and fade away totally by the time they hit the left edge. That's all that's left to get the picture to 100%, but I found no other connections that were bad.
If I unplug the right hand side connector from the T-CON board, so that the right hand side of the LCD goes blank, the remaining lines disappear on the left. This tells me that these remaining horizontal lines might be from a bad T-CON board. So I'm replacing that board next. Hopefully, it's 100% after that. I don't have a lot of faith in it though.
If it doesn't fix it, it'll make an excellent secondary/bedroom/workout TV lol. The picture is nearly perfect now.
Protonus did replacing the tcon board fix it on the end?
One of the design engineers from Samsung is watching this doing a face palm. Come on tell us which £0.01 component is faulty :-)
Coolkeys2009 Knowing Samsung, they probably put put a counter where after a certain number of hours of screen on time, it corrupts some config in the firmware of one of the chips, or some other form of planned obsolescence.
+Razor2048 this is possible I remember when Epson printers did this
Razor2048 I can believe it was caused by a problem they missed or something they skimped on but I don't believe Samsung would bother spend the extra money to design in a fault. LOL
Carbon cricket FX This would actually be the stupidiest thing a manufacturer could ever do. Planned obsolence at the expense of staining brand quality just means a swifter way to bankrupicity.
Crimson Sunrise i know but they genuinely did after a set number of prints they said they needs servicing mine did www.reportsfromearth.com/155/designed-to-fail-planned-obsolescence-in-printers-tricks-to-fix-them/
hello Dave I was wondering if you know a good book on learning to troubleshoot and repair TVs LCD. Iv been thinking about buying "my best collection of Electronics Repair Articles"
Looks like a chip on glass warming up problem to me, try your hot air iron round the outer edge of the screen while its turned on.
You can buy a working T-Con board on E-Bay for about or less than 60.00....From a HDTV with a broken screen they sell all the good parts from it....power board and main boards....inverter...
i think, that there is something wrong with internal power rails - when it drives pixel bright and relaxes transistor, it has lack of power to return transistor back. or there is current leakage in the panel itself from horizontal lines to vertical
Well, looks like I was wrong about the TAB's being the issue. It looks very similar to a tab issue, but upon your further investigation, it became obvious that was not it. Ah well, those panels are a marvel to see anyway, so wasn't a complete waste of time.
This is an internal panel short, you can narrow down which signal lines the shorts on by putting capton tape over some of the pins on the ribbon end, on one of the 2 ribbons going to the panel buffer boards
Sometimes using this method you can get rid of the lines while retaining a good picture, also one of the ics on the tcon will be red hot while that shorts connected to it, that's why the lines slowly appear as the ic starts to struggle with the overload and the chip heats up
+EEVBlog If you still have the LCD TV Dave, have you considered the clock management?
Clock based timing issues could potentially explain the ghosting as well as the lines which could be following your screen input.
But to see if the lines are just input based as in menues etc just hook the TV to a PC as the secondary screen and make the background white so the TV only shows a "pure" white screen. If a "pure" color can be shown without lines will help you eliminate possible sources for the fault.
Did either Dave mention if all the inputs produced the same result? Especially curious about the other HDMI inputs as well as Component and VGA (does it have this one?) inputs. I don't remember seeing any of the others tested on either video so far. Only the PC (HDMI). Just isolating the issue.
Either way, I love these dumpster repair vids. Very educational to hear Dave's thought process on troubleshooting and testing. I hope they can figure it out!
I'm really happy that you did a part 2, but in accordance I'd be way more thrilled if you did a part 3 and fix this puppy. I know it will take all the guns but please can you do it. Love your videos rodders520.
After seeing what you have tested and poked i would call a dry joint on the processor board... And if i had to point to the exact bit i would say a bad earth on the LVDS connection.
So, what happens if you put a video signal on it and place it in a mode so no tv generated text is displayed? Also, it is strange that when powered up, the lines ramps up in brightness.
Did you guys ever throw a new T-con board in there and see if it worked? Did you fix it at all somehow? I've got a Toshiba 42" TV I'm trying to fix that is doing the exact same thing.
if the image is filling a column, it _could_ possibly be an issue other than bad column drivers or connections. If you see weird pattern in how a column fills, then look at the horizontal drivers activating/leaking onto multiple rows at once.
*and you guys consider it later in the video, good deal!
I was initially suspecting that some of the power rails' voltages were drifting after being turned on, but then when you noticed that the streaks were associated with the text, that made that seem unlikely. (And when you tested the voltages, it had presumably been on for several seconds.) But some of the recent replies to Mike's comment explain how that could actually be the cause. Weird, though, that the text that spans almost the full width of the screen at 22:40 doesn't cause streaks. Maybe that's because it's not as bright as the other text, as Mila Miglia said-the bright icons at 22:25 certainly cause brighter streaks.
I believe it's to do with the LCD itself I've seen this before where the LCD broke and caused lines and dead pixels so a replacement of the LCD would be required
It is entirely possible is not the LCD if so it's the caps which have been fixed but then the tecon board can be the problem but then if it's not that then it's the main board but I've not seen TVs that are built like this and I don't believe after all this time that it's possible for me or most people to be any help but good video I really found it interesting how much could of been wrong with it
got this issue on my tv and just uploaded a video, with a desktop background (a still image with lots of different text /game icons the lines literally cover the screen after being on for a minute or so
Did he trickle some flux under the BGA chips ?
Hi i have an medion LED tv with this exact T-con board. the problem I am having is that I dont have any picture, but the sound and backlighting work. What is the best way to troubleshoot this board?
HI dave, I have the exact same tv and am experiencing the exact same problem as in this video. Did you end up finding the solution for the problem? Would like to find out if there was ever a fix for it, Cheers.
Well, I have a Samung UN40D5500 from 2012 and in past november 2021 went into this same exact problem. I took it to the technical service here it was until now, and being January 2022, service called me yesterday and told me that TV couldn't be fixed since for they the issue is the panel itself and over here is very complicated to get a replace, and very expensive.
I suspect this being a software issue... There are filters implemented inside an FPGA which do motion estimation and such things.. Good chance they aggregate some values and due to faulty memory or such don´t clear the buffer or whatever.. So you get this "accumulation" of bad values.
Dave! Check Vgh and Vgl voltage. please check the voltage with a oscilloscope.
The display on my smartwatch did the same thing, with the blue and red vertical lines as well as the horizontal 'scan-lines'. The fault fixed itself over the course of a day or so, and appeared to have come from the wireless charger. Probably not relevant but it could be... :D
Check out the way they matched the length of the traces in that cable. The railroad could do this on the inside track on curves.