Ran into the identical problem with my mother's 32" Samsung. Both LED strips were bad on it. There were actually burn marks around the LED's that most likely initially dead shorted, before opening. The set only lasted 6 months. Since this was a black Friday purchase, the light strips were half the cost of the TV, so I purchased a new one for her and listed the individual boards on Ebay. The only inquiries that I have had for them were from people asking if I still had the LED backlights...............
The main problem is no one is telling the costumer to keep the backlight settings low, just about all the ones I repair ( 5 a day now in the uk) are set at 100% , if they were at 75% they would last years longer. I set mine after repair at 45% and the picture is fine.
This is no different than back in the CRT days.In that all important drive to have the brightest picture with the most contrast, manufactures made tubes with very dark glass to reduce reflections. Then they cranked the sh1t out of the tube to make it a table lamp not a TV, and people wondered why the picture tube was shot after 4 years, when their old set lasted 20+ years,
$40 for 5 new 10 LED strips for a Sharp 43" Roku TV. Mine had 4 of the 5 strips with 1 or 2 bad LED's I could power it up and see one strip flash and then go out. Each LED on the strip has a + - test point and in continuity mode you can see each one faintly glow if good. I tried to replace the bad ones and got them to all fire but the LED's were the wrong value and didn't glow bright at all. It worked but I had dark spots on the screen and then they too failed after about 30 minutes. I could not find the correct value LED's (maybe 6V 250ma? super bright!) so just bought 5 new strips and all is well. Be very careful with the LED panel when lifting off the diffusers, its pretty thin and fragile. Best is to lay it panel face down and lift the backlights off the supported panel. There were 3 layers of diffusion under the LCD. Fresnel, diffuser and opaque layer.
Client must be crazy. Easyist repair ever. It's time consuming but if you have some spare LEDs it would only take an hour, then good as new. Shame he never let you finish it.
I agree, but that wasn't my choice. I offered to fix it, but then I am going through a 3rd party. The guy that brought it to me is not the owner, he is the system integrator so I am dealing with an installer, giving him the diagnosis, and he is dealing with the owner. Installer called me and said throw it together and I will pick it up.
Easy repair, easy to prevent also. Turning down the backlight strength to 50% will prevent over voltage. You also won't notice much of a difference in picture quality.
I've come across the same problem and the problem usually is the power supply. Symptoms are exactly the same: the 12V line is hovering somewhere near 9V and backlight is flickering. I suspect there is a problem with the PFC chip underneath the power supply since the voltage on the main reservoir capacitor is at 330V, not 390V, where it should be. Unfortunately I haven't been able to find the chip so I can't verify this, so I have just replaced the whole board.
I doubt that , 9 times out of 10 it's a failed backlight. If one shorts it can flicker , but just testing to see which backlights have failed and replacing them is easy.
12voltvids I went on Samsung support site and they offer zero zilch schematics... they focus most of the diagnostic on useless info about the main board port pin id's etc.. no real relevant service info.
Ah yeah, LED backlight failures. I don't even worry about getting the LEDs to replace them with since they're harder to find, I just use a diode. If it's just a couple of LEDs out you can't really tell once it's back together because of the diffuser. I also tell people to turn their backlights down on their LED TVs a bit to lower the load on these circuits, it will extend their life. Often they are set to 100% at the factory.
Oh also, didn't know if you knew about these but a 500 pack of some backlight leds - www.aliexpress.com/item/500PCS-LG-LED-Backlight-1210-3528-2835-1W-100LM-Cool-white-LCD-Backlight-for-TV-TV/32685786152.html?ws_ab_test=searchweb0_0,searchweb201602_2_10056_10065_10055_10068_10067_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_7&btsid=9b56e2a0-3d2d-4d0e-8774-d410967da681 I might try ordering some eventually myself.
If you're not going to give the engineer the time and resources to fix something you shouldn't waste their time in the first place. Your customer is a tool.
I'm dealing with a system integrator that removed the set from the end customer and brought it to me. I would love it if he said keep it, because then I would find the LED that is out and fix it like I did that Philips LED that went south a few years ago. Same thing. A bunch of LEDs in series, so if one goes you loose the string, and the way these units are set up if you loose a string it upsets the current draw on the PSU and throws an over or under current fault that shits the set down.
Yeah its the led strips. I've repaired about 5 of this model now and every one of them had multiple LEDs burnt out. Can get a brand new set for 20 bucks on Ali Express, they come from China and take awhile to get here but they work good.
I like Samsung. I have many of them here. The problem with the LED backlights failing is more than likely people running them at 100% I keep my only LED set at 80%. Same for my Plasma sets. I keep them at 7 or 8. Never run them at max, too hard on components.
Never mind, a good bit of diagnostics, still enjoyable to see you have a go :-D. If the owner had not been so stupid, you would have had time to do more to the set. I see its as the owners loss, not giving a pro like you the time is just silly :-(. Hey i thought you were going to pause the video making while concentrating on your job, dont wear yourself out :-(.
Troubleshooting my first free-to-me-dead-LED-TV. Samsung UN48j5000. PSB is L48MSF_FDY BN44-00852A, LED strips are: 2015 SVS48 FCOM FHD DOE A RIGHT REV1.2 150605 LM41-00120Q_LM4100149A. No joy with SM or schematic search. I pulled the back off. Saw no bulged caps, black R's, nor burn marks on any of the three boards. At first plug in, I heard BZZT...BZZT....BZZT about once/sec. I was looking at the back-of-the-set when this occurred. Sounded like the noise was coming from behind the Main board. I also detected a faint whiff of electricity/ozone/something getting hot. Sounded like arcing. With power to backlight connector removed, I was able to verify V's to Main board as OK. Stripped it further down so I could view the backlight strips. Found bad burn mark on strip 2 up from bottom, on far right hand side, between second-to-last & last LED. Burn area nearly full 'height' of tall trace (8mm) and about 13mm side-to-side!! WTH? All 32 LEDs (4 strips x 8 LED's/strip) stil worked when tested with bench supply. Attempted to repair burned area but no joy. I may just cut the end off & complete the series strip ckt with solder, then see of the PS will power up, stabilize and light the remaining 31 LEDs. If not, arcing may have damaged something in backlight driver ckt on backside of PSB. I've done a close visual inspection. Didn't notice anything. Out of all the videos I've watched, only seen one with a burn mark on a strip. Why in the world would arcing begin between two LEDs? Very odd failure. Perhaps at this place in the series diode string the voltage must have been high enough to arc to the metal backing of the strip? After some PSB tracing I discovered that though there are four pairs of backlight wires (+-1, +-2, +-3, +-4), there is only a single series ckt AND a single backlight driver. Not two or more like some larger sets. 3V x 32 LEDs = 96V. I wonder if the BL driver ckt raised the driving V to its MAX attempting to bridge the growing burn area which looked like an open to it? Interested in your thoughts!
I finally figured it out. The strip I repaired drew way too much current. Must have been very damaged. Another LED on another strip began to sizzle so I immediately pulled the plug. Found local shop selling two right-hand-strips. Installed these and now all four strips (32 LEDs total) lit up fine and bright! Voltage & current draw for backlight ckt and drivers is back to normal. Learned a lot fixing this one. Second issue has to do with a few vertical stripes on the screen. I enjoy your videos! BTW, you helped me disassemble an old Sony Hi-8 camcorder and fix it. Ditto for an old mid-80's JVC HiFi VCR deck I still use on a regular basis! Much thanks for lighting the way!
My Samsung TVs backlights won’t turn on if my power supply is screwed into the back of the tv like it’s suppose to. But as soon as I take it if or set something between the tv and the board, then my back lights turn on. What could cause this? Is it save if I put electrical tape on the metal part of the tv where the ground screws go?
Ok quick test on samsung tv's you can do and this is from samsung GSPN fast track manuals so it is proven... All samsung sets from the C series up will self power on the PS when you disconnect the main from the PS by removing the cable between them. When plugging in the set at this state the backlights should come on immediately and stay lit at full brightness and the power supply voltages should come on. If you dont get backlights or backlights are erratic you can eliminate the main from the equation. I saw in the video the BL was pulsating when you disconnected the main it was still pulsating.. knew immediately it wasnt a main issue and it had BL failure.. its been non stop with so many LED sets today its not funny!
Yes I know the main board was fine from this test. I am still working on this set trying to find the problem, as all the LEDs test good. I took a battery and was able to light every stupid light on strip glows, and they all test OK, but they don't light when connected to the power supply board. Driving me mad, as I took the screen apart expecting to find a dead LED, but nope they all test OK. Any ideas?
12voltvids the high speed switching diodes are known to short on these boards. The larger black ones in the backlight drive area. Check them. Since the leds are good then it's obviously somewhere on the ps.
Yes that is what I am thinking. I took that screen apart expecting to find a bad LED, but every bloody one of them tested good. I know the main board was fine, as it ended up in an identical set with a bad main board, so now this set it mine to play with, and I suspect a bad diode in the psu. I just haven't got around to checking them all out yet.I would like to see if I can get it going just for fun because now it has a bad main board that reboots when the volume is changed but for a display where the volume is never changed it would probably work just fine, and I have a use for it as a digital picture frame if I can get the backlight problem solved.
A schematic for the power supply would be great.I did check the power diodes, they are NUR460p and none of them test as short, but I am thinking that they may be going leaky under load? What do you think, replace all of them and see if that makes any difference?
Took entire tv apart and tested each LED strip. ALL GOOD. Replaced PS board and same result. TV starts up, i see LEDs come on and then go out. Flashing red 2 times and then it tries to start up again and again.... When I disconnect either one of the ribbon cables going from main board to panel the backlights stay on but when I connect both, the less go out. This one has me stumped.. Owner says they were watching tv and it just went out.... Let's see who can solve this one..
I had the exact same TV, and the bottom half LED strip died. I could still watch TV but the bottom half would be darker than the top half. That was the last time I bought an edge-lit TV, and a Samsung TV. It only lasted about 5 years, which was a huge disappointment.
@@12voltvids My Panasonic plasma was good and my folks have been using a Samsung plasma (720p) for 10 plus years without issue... there was some pretty bad retention at one point, but it's gone now. I think edge-lit makes me nervous more than anything.
I have a 50" Samsung with a bad panel. Has a green line running down the screen. I gave it to my kids to play video games on. Still has a beautiful picture other than a thin green line that goes top to bottom. It is starting to burn , so eventually the phosphor will burn and it will be a black line.
James Last that's odd because a 1x blink points to an A board communication failure.. panel failures generally produce 7 blink codes due to error feedbacks to the su and sd boards trying to drive the panel.
So what happens when you have standby light, LEDs go on when you disconnect PS from Main board, but TV will not turn on LED's when you power up and plug PS into main board? This one got me....
My only issue with my Samsung LED tv UN55FH6030F is the backlight. when I increase the backlight to 12 and up the screen will get very dark and when it’s on 11 it is not bad but not presenting a good quality of image and it’s dim. Appreciate your advice if this could be the Capacitor problem or the LED light strips? Thanks
awesome bud. i have a samsung, backlights work, all voltages are coming out of power supply board. whats your thoughts on Tcon or video card bad? i have no sound either.
My tv turns on but is very dim no matter what I do to the settings, but you still can faintly see the picture. Do you think some of the led lights are out on the backlight or maybe a motherboard??
I fix the broken LED light and I test them every thing was good. After 1 hour using tv the back lights gots again dark . Where is come from this problem ?
might be another led failing again. when one goes bad, voltage fluctuates and can stress others too hard, too. I saw this in Led bulbs, once one led fails, even if you repair it, others fail soon.
the design is not good, many leds in series, this makes the weakest one get stressed by higher voltage. Once one fails, next one is stressed out. In li-ion batteries, they use balancers to evenly charge them, you can see an example in which they couldn't cheap out on parts, as it could explode. On leds, they don't care.
Thanks for the video, but being technologically challenged I need advice on how to get started. My 60" Samsung LED backlight went out, and a Geek Squad guy ordered a board for me. The board just got here today and I'm going to try to tackle this myself. I have just one basic question: If the TV is attached to a stand (sitting on a desk), is it necessary to take the stand off to remove the back panel? Once I get the back off I'm sure I can compare the new board to the old one to replace it. Thanks.
my samsung ua40f6300 no backlight but with sound at audio output connected to my amplifier and i see image by flashlight,whats possible cause,led driver is in power supply board,
There are a number of possible causes. It could be a single failed LED inside the panel. I have had a resistor on a set similar to this go open. It was a 10 ohm resistor in the PFC (power factor correction) circuit that sent up in value to about 250 ohms but that put the set into a shut down mode with 5 double blinks of the power light.
Question. My tv flickers with main board and led connected. When i unplug the led the flickering stops and i hear the samsung sound but no picture (ofcourse) any suggestions?
Hey. Good video. I’m having almost the same problem. I have a 75 inch tv. When everything is plug normal. It turn on off on off. It’s stays on for less then 3 second. If I unplug the main board. The led start freaking out just like that tv does in this video. BUT if I leave the main board plug and unplug one of the LED Plug (this one has 2 plugs).... the tv stays on and you can heard the volume if I press it up or down. Do you know if it’s one of the LED taking too much volts or its the main board?
12voltvids I open the tv. And got to the LED BAR. Theses are not across like the others tv. Theses one are in the side. Left and right. I believe it’s not the LED. Because (there are 4 LED). If I disconnect one of them the tv stays on. For example. RIGHT TOP AND LEFT TOP gotta be connect at the same time for both to work. RIGHT BOTTOM and LEFT BOTTOM gotta be connect at the same time for left and right bottom to stays on. But this is what is happening. If I disconnect one of the top LED , The Tv stays on but only left and right bottom working.,,, if I disconnect one of the bottom, the tv stays on but only left and right top LED works.
have you ever come across double imaging and ghosting on a Samsung it's a bout 5 years old I have tried putting tape on the ribbon but it still will come back model no 46D5000
derek mcdonald double imaging especially jittering is always a panel failure, any horizontal lines or horizontal effects are always panel related due to tab bond failures in the panel. Tcon issues will generally be loss of video entirely, symmetrical vertical bars and similar. Any localized effects are always panel related because lvds data to tcon are in 8-10-12 bit data streams and will effect the image globally when you get failures outside of the panel... thin vertical and horizontal localized lines... shadowing, ghosting and horizontal jittering is always panel related
Honestly panels are the most expensive part in the tv and is generally not cost effective to repair. they tend to cost equal to if not more than the cost of replacing the set
I am still hopeful that the unit will be abandoned and then I can proceed with ripping the panel apart and checking out the lights. I have some strips from a broken screen set. The unit is sitting in my garage awaiting pickup
@@allenfleckney5969 Hi I came across your reply to a video and wondered if you could help with backlight leds for Samsung le46c750r2k ? Or possibly repair it for me ???
I hear you. Nothing lasts these days. I would really like an OLED set, but it is hard to justify that kind of money on unproven technology. I still like my old Plasma sets they have proven to be reliable for me. I picked up a 4K set for the studio, and got the cheapest one of half decent quality I could find. Only 420.00 so if that only last a few years I won't feel so bad.
I feel the same way about "unproven technology". When SSD's came out for computers, a tech for a local hospital I know was raving about how they bring new life into old computers because of their speed. I simply felt they were TOO NEW to fully trust with valuable data. So I have waited a few years to make that leap. Guess I am ABOUT ready, lol!
@@TortureBot you're right. when ssd fails, data impossible to retrieve, as it is aplit over multiple chips. From Hdds you may still recover something. For surface errors, you can skip the area and still get most of files back. Had a WD hdd with bad sectors, I even partitioned it such that empty space was covering the bad areas and could continue using it for non-important backups, i.e. backups of another backup drive.
The reason for the high voltage is the LEDS are in series. This allows low current. If the LEDs were in parallel the voltage would be low, but the current high, and this would require a laager transformer, and heavier wiring. Of course the down side of series LEDs is if one goes bad, you loose the entire strip.
Samsung makes good TVs but if you cheap out then you get what you pay for Sony Samsung are pretty good tv companies. At the moment I have a higher end Vizio witch is not bad but I have more Samsung TVs and haven't had any problems
Allen Fleckney I hate to tell you that Sony has its fair share of panel failures where as it has less backlight failures it has plenty of tab bond and internal tcon failures.. and those damn android b,c, and d series Xbr sets have been a nightmare!
yeah.. BL failures arent Sony's weakness. its their main boards.. they are very probematic! Even the D series XBR sets are crapping out left and right! Even the DPS boards are crapping out on those XBR sets
If you bypass the backlight you are adding extra voltage to the others meaning they will burn out quicker. Any 3v led from any TVs will work, it doesn't have to be the same strip
Correct, this will stress others, but at least it gets more life out of the set. If this set ever gets given to me I will be researching further, but the owner said he wants it back, so it went back together.
It may be ok to by pass one 3.5v led even though I don't advise it, but yesterday I did an LG 49 inch that had 12 faulty LEDs , so you can't by pass 40 volts they have to be replaced. These LEDs were advertised as having 10.000 hours. Lucky if they see 1000.
I doubt that many of the LEDs that are advertised as having 20,000 live spans will last beyond 1 - 2000 hours. I am changing more LEDs at my house than the old compact fluorescents that did last 10 years. I have CFLs that are 12 years old and still going strong, but the LEDs seem to only last 2-3 years, and those ones were really expensive too.
I have a Samsung UN39FH5000FXZA screen went black with blinking lights. When I disconnect the led plug from the power board I get sound?? Would that be the T-Con board??
Ran into the identical problem with my mother's 32" Samsung. Both LED strips were bad on it. There were actually burn marks around the LED's that most likely initially dead shorted, before opening. The set only lasted 6 months. Since this was a black Friday purchase, the light strips were half the cost of the TV, so I purchased a new one for her and listed the individual boards on Ebay. The only inquiries that I have had for them were from people asking if I still had the LED backlights...............
The main problem is no one is telling the costumer to keep the backlight settings low, just about all the ones I repair ( 5 a day now in the uk) are set at 100% , if they were at 75% they would last years longer. I set mine after repair at 45% and the picture is fine.
This is no different than back in the CRT days.In that all important drive to have the brightest picture with the most contrast, manufactures made tubes with very dark glass to reduce reflections. Then they cranked the sh1t out of the tube to make it a table lamp not a TV, and people wondered why the picture tube was shot after 4 years, when their old set lasted 20+ years,
$40 for 5 new 10 LED strips for a Sharp 43" Roku TV. Mine had 4 of the 5 strips with 1 or 2 bad LED's I could power it up and see one strip flash and then go out. Each LED on the strip has a + - test point and in continuity mode you can see each one faintly glow if good. I tried to replace the bad ones and got them to all fire but the LED's were the wrong value and didn't glow bright at all. It worked but I had dark spots on the screen and then they too failed after about 30 minutes. I could not find the correct value LED's (maybe 6V 250ma? super bright!) so just bought 5 new strips and all is well. Be very careful with the LED panel when lifting off the diffusers, its pretty thin and fragile. Best is to lay it panel face down and lift the backlights off the supported panel. There were 3 layers of diffusion under the LCD. Fresnel, diffuser and opaque layer.
yes that is how to fix.
Client must be crazy. Easyist repair ever. It's time consuming but if you have some spare LEDs it would only take an hour, then good as new. Shame he never let you finish it.
I agree, but that wasn't my choice. I offered to fix it, but then I am going through a 3rd party. The guy that brought it to me is not the owner, he is the system integrator so I am dealing with an installer, giving him the diagnosis, and he is dealing with the owner. Installer called me and said throw it together and I will pick it up.
Easy repair, easy to prevent also. Turning down the backlight strength to 50% will prevent over voltage. You also won't notice much of a difference in picture quality.
@@12voltvids He used your diagnosis and is replacing the tube by himself.
LED Driver on the main board or the power board will do it, most times it’s a capacitor or IC Circuit easy change
I've come across the same problem and the problem usually is the power supply. Symptoms are exactly the same: the 12V line is hovering somewhere near 9V and backlight is flickering. I suspect there is a problem with the PFC chip underneath the power supply since the voltage on the main reservoir capacitor is at 330V, not 390V, where it should be. Unfortunately I haven't been able to find the chip so I can't verify this, so I have just replaced the whole board.
I doubt that , 9 times out of 10 it's a failed backlight. If one shorts it can flicker , but just testing to see which backlights have failed and replacing them is easy.
The power supply connector lists the voltage at 9 volts which is what it is delivering.
Which is what I was prepared to do but the owner wanted it back to get a second opinion.
12voltvids I went on Samsung support site and they offer zero zilch schematics... they focus most of the diagnostic on useless info about the main board port pin id's etc.. no real relevant service info.
the power board is the L42SFV?
Ah yeah, LED backlight failures. I don't even worry about getting the LEDs to replace them with since they're harder to find, I just use a diode. If it's just a couple of LEDs out you can't really tell once it's back together because of the diffuser. I also tell people to turn their backlights down on their LED TVs a bit to lower the load on these circuits, it will extend their life. Often they are set to 100% at the factory.
My new 4K set came with them set to 20 from the factory. I generally run them at about 12 (20 is full) and the picture looks great at that level.
Oh also, didn't know if you knew about these but a 500 pack of some backlight leds - www.aliexpress.com/item/500PCS-LG-LED-Backlight-1210-3528-2835-1W-100LM-Cool-white-LCD-Backlight-for-TV-TV/32685786152.html?ws_ab_test=searchweb0_0,searchweb201602_2_10056_10065_10055_10068_10067_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_7&btsid=9b56e2a0-3d2d-4d0e-8774-d410967da681
I might try ordering some eventually myself.
the LEDs are pretty easy to get and replace actually. shopjimmy sells packs of them all day long lol
If you're not going to give the engineer the time and resources to fix something you shouldn't waste their time in the first place. Your customer is a tool.
I'm dealing with a system integrator that removed the set from the end customer and brought it to me. I would love it if he said keep it, because then I would find the LED that is out and fix it like I did that Philips LED that went south a few years ago. Same thing. A bunch of LEDs in series, so if one goes you loose the string, and the way these units are set up if you loose a string it upsets the current draw on the PSU and throws an over or under current fault that shits the set down.
What they need is a zener diode in series with every LED ... that way, when an LED fails like that, it will still allow power to flow.
Yeah its the led strips. I've repaired about 5 of this model now and every one of them had multiple LEDs burnt out. Can get a brand new set for 20 bucks on Ali Express, they come from China and take awhile to get here but they work good.
Are they easy to fix? Mine went half dark (barely visible) and right side is normal.
Great bit of information in the comments... Thanks ....Leo
yes.. samsung make good tv ..see all video 12volt repairing about samsung TV
I like Samsung. I have many of them here. The problem with the LED backlights failing is more than likely people running them at 100% I keep my only LED set at 80%. Same for my Plasma sets. I keep them at 7 or 8. Never run them at max, too hard on components.
To be honest Samsung backlight failure is rare compared to Toshiba (Europe Vestel) and LG
We used to call Toshiba "Toshitba" at work when I was working at the shop.
Is good tutorial..thanks
Never mind, a good bit of diagnostics, still enjoyable to see you have a go :-D.
If the owner had not been so stupid, you would have had time to do more to the set.
I see its as the owners loss, not giving a pro like you the time is just silly :-(.
Hey i thought you were going to pause the video making while concentrating on your job, dont wear yourself out :-(.
It's not a backlight problem. Power supply drops the voltage.
Troubleshooting my first free-to-me-dead-LED-TV. Samsung UN48j5000. PSB is L48MSF_FDY BN44-00852A, LED strips are: 2015 SVS48 FCOM FHD DOE A RIGHT REV1.2 150605 LM41-00120Q_LM4100149A. No joy with SM or schematic search. I pulled the back off. Saw no bulged caps, black R's, nor burn marks on any of the three boards. At first plug in, I heard BZZT...BZZT....BZZT about once/sec. I was looking at the back-of-the-set when this occurred. Sounded like the noise was coming from behind the Main board. I also detected a faint whiff of electricity/ozone/something getting hot. Sounded like arcing. With power to backlight connector removed, I was able to verify V's to Main board as OK.
Stripped it further down so I could view the backlight strips. Found bad burn mark on strip 2 up from bottom, on far right hand side, between second-to-last & last LED. Burn area nearly full 'height' of tall trace (8mm) and about 13mm side-to-side!! WTH? All 32 LEDs (4 strips x 8 LED's/strip) stil worked when tested with bench supply. Attempted to repair burned area but no joy. I may just cut the end off & complete the series strip ckt with solder, then see of the PS will power up, stabilize and light the remaining 31 LEDs. If not, arcing may have damaged something in backlight driver ckt on backside of PSB. I've done a close visual inspection. Didn't notice anything.
Out of all the videos I've watched, only seen one with a burn mark on a strip. Why in the world would arcing begin between two LEDs? Very odd failure. Perhaps at this place in the series diode string the voltage must have been high enough to arc to the metal backing of the strip? After some PSB tracing I discovered that though there are four pairs of backlight wires (+-1, +-2, +-3, +-4), there is only a single series ckt AND a single backlight driver. Not two or more like some larger sets. 3V x 32 LEDs = 96V. I wonder if the BL driver ckt raised the driving V to its MAX attempting to bridge the growing burn area which looked like an open to it?
Interested in your thoughts!
I finally figured it out. The strip I repaired drew way too much current. Must have been very damaged. Another LED on another strip began to sizzle so I immediately pulled the plug. Found local shop selling two right-hand-strips. Installed these and now all four strips (32 LEDs total) lit up fine and bright! Voltage & current draw for backlight ckt and drivers is back to normal. Learned a lot fixing this one.
Second issue has to do with a few vertical stripes on the screen.
I enjoy your videos! BTW, you helped me disassemble an old Sony Hi-8 camcorder and fix it. Ditto for an old mid-80's JVC HiFi VCR deck I still use on a regular basis! Much thanks for lighting the way!
My Samsung TVs backlights won’t turn on if my power supply is screwed into the back of the tv like it’s suppose to. But as soon as I take it if or set something between the tv and the board, then my back lights turn on.
What could cause this? Is it save if I put electrical tape on the metal part of the tv where the ground screws go?
Ok quick test on samsung tv's you can do and this is from samsung GSPN fast track manuals so it is proven... All samsung sets from the C series up will self power on the PS when you disconnect the main from the PS by removing the cable between them. When plugging in the set at this state the backlights should come on immediately and stay lit at full brightness and the power supply voltages should come on. If you dont get backlights or backlights are erratic you can eliminate the main from the equation. I saw in the video the BL was pulsating when you disconnected the main it was still pulsating.. knew immediately it wasnt a main issue and it had BL failure.. its been non stop with so many LED sets today its not funny!
Yes I know the main board was fine from this test. I am still working on this set trying to find the problem, as all the LEDs test good. I took a battery and was able to light every stupid light on strip glows, and they all test OK, but they don't light when connected to the power supply board. Driving me mad, as I took the screen apart expecting to find a dead LED, but nope they all test OK. Any ideas?
12voltvids the high speed switching diodes are known to short on these boards. The larger black ones in the backlight drive area. Check them. Since the leds are good then it's obviously somewhere on the ps.
Yes that is what I am thinking. I took that screen apart expecting to find a bad LED, but every bloody one of them tested good. I know the main board was fine, as it ended up in an identical set with a bad main board, so now this set it mine to play with, and I suspect a bad diode in the psu. I just haven't got around to checking them all out yet.I would like to see if I can get it going just for fun because now it has a bad main board that reboots when the volume is changed but for a display where the volume is never changed it would probably work just fine, and I have a use for it as a digital picture frame if I can get the backlight problem solved.
Let me know if i can help with any of these sets.. I have full access to Samsung GSPN for bulletins on all their sets..
A schematic for the power supply would be great.I did check the power diodes, they are NUR460p and none of them test as short, but I am thinking that they may be going leaky under load? What do you think, replace all of them and see if that makes any difference?
Took entire tv apart and tested each LED strip. ALL GOOD. Replaced PS board and same result. TV starts up, i see LEDs come on and then go out. Flashing red 2 times and then it tries to start up again and again.... When I disconnect either one of the ribbon cables going from main board to panel the backlights stay on but when I connect both, the less go out. This one has me stumped.. Owner says they were watching tv and it just went out.... Let's see who can solve this one..
I had the exact same TV, and the bottom half LED strip died. I could still watch TV but the bottom half would be darker than the top half. That was the last time I bought an edge-lit TV, and a Samsung TV. It only lasted about 5 years, which was a huge disappointment.
I have a couple of Samsung sets that have been good. My plasma sets get heavy use and they have all been great.
@@12voltvids My Panasonic plasma was good and my folks have been using a Samsung plasma (720p) for 10 plus years without issue... there was some pretty bad retention at one point, but it's gone now.
I think edge-lit makes me nervous more than anything.
I finally ran into a plasma panel failure. The dreaded Panasonic 1 blink code. Iam parting it out with tearful eyes. 58" of beauty.
I have a 50" Samsung with a bad panel. Has a green line running down the screen. I gave it to my kids to play video games on. Still has a beautiful picture other than a thin green line that goes top to bottom. It is starting to burn , so eventually the phosphor will burn and it will be a black line.
I've just repaired a Panasonic 50 inch with the one blink code, it was the main board, are you sure it's the panel.
Replaced the A board but no luck. That usually means a bad panel.
James Last that's odd because a 1x blink points to an A board communication failure.. panel failures generally produce 7 blink codes due to error feedbacks to the su and sd boards trying to drive the panel.
James Last
So what happens when you have standby light, LEDs go on when you disconnect PS from Main board, but TV will not turn on LED's when you power up and plug PS into main board? This one got me....
enjoyable, thank you ...
My only issue with my Samsung LED tv UN55FH6030F is the backlight. when I increase the backlight to 12 and up the screen will get very dark and when it’s on 11 it is not bad but not presenting a good quality of image and it’s dim.
Appreciate your advice if this could be the Capacitor problem or the LED light strips?
Thanks
Thx a lot! It's very useful!
awesome bud. i have a samsung, backlights work, all voltages are coming out of power supply board. whats your thoughts on Tcon or video card bad? i have no sound either.
Please I need power supply voltage label
Does Vizio's do the same with the power not coming on because of a bad LED? thanks for posting
All led tvs will not display a picture if the backlight is out. Some you can do the flashlight test on.
My tv turns on but is very dim no matter what I do to the settings, but you still can faintly see the picture. Do you think some of the led lights are out on the backlight or maybe a motherboard??
I fix the broken LED light and I test them every thing was good.
After 1 hour using tv the back lights gots again dark .
Where is come from this problem ?
might be another led failing again. when one goes bad, voltage fluctuates and can stress others too hard, too. I saw this in Led bulbs, once one led fails, even if you repair it, others fail soon.
the design is not good, many leds in series, this makes the weakest one get stressed by higher voltage. Once one fails, next one is stressed out. In li-ion batteries, they use balancers to evenly charge them, you can see an example in which they couldn't cheap out on parts, as it could explode. On leds, they don't care.
Thanks for the video, but being technologically challenged I need advice on how to get started. My 60" Samsung LED backlight went out, and a Geek Squad guy ordered a board for me. The board just got here today and I'm going to try to tackle this myself. I have just one basic question: If the TV is attached to a stand (sitting on a desk), is it necessary to take the stand off to remove the back panel? Once I get the back off I'm sure I can compare the new board to the old one to replace it. Thanks.
Some TVs it is necessary to remove the stand, and others it can be removed with the stand on it.
Thanks.
Are all Samsung Led's have parts that are interchangeable?
Everything works on my Samsung tv but the picture. Is it Junk? It’s only 3 years old
More than likely a single bad LED.
my samsung ua40f6300 no backlight but with sound at audio output connected to my amplifier and i see image by flashlight,whats possible cause,led driver is in power supply board,
There are a number of possible causes. It could be a single failed LED inside the panel. I have had a resistor on a set similar to this go open. It was a 10 ohm resistor in the PFC (power factor correction) circuit that sent up in value to about 250 ohms but that put the set into a shut down mode with 5 double blinks of the power light.
Question. My tv flickers with main board and led connected. When i unplug the led the flickering stops and i hear the samsung sound but no picture (ofcourse) any suggestions?
Probably a bad led. They are about as reliable as an old Yugo or lada.
Is backlight bleed fixable?
Hey. Good video. I’m having almost the same problem. I have a 75 inch tv. When everything is plug normal. It turn on off on off. It’s stays on for less then 3 second. If I unplug the main board. The led start freaking out just like that tv does in this video. BUT if I leave the main board plug and unplug one of the LED Plug (this one has 2 plugs).... the tv stays on and you can heard the volume if I press it up or down. Do you know if it’s one of the LED taking too much volts or its the main board?
Probably the LED
12voltvids okay. like I said. This tv has 2 plugs for the LED. How could I test it without having to take screen apart. I have a power supply
@@primeramusic3593 Check the voltage drop across each plug
12voltvids I open the tv. And got to the LED BAR. Theses are not across like the others tv. Theses one are in the side. Left and right. I believe it’s not the LED. Because (there are 4 LED). If I disconnect one of them the tv stays on. For example. RIGHT TOP AND LEFT TOP gotta be connect at the same time for both to work. RIGHT BOTTOM and LEFT BOTTOM gotta be connect at the same time for left and right bottom to stays on. But this is what is happening. If I disconnect one of the top LED , The Tv stays on but only left and right bottom working.,,, if I disconnect one of the bottom, the tv stays on but only left and right top LED works.
I checked one of the plugs. And L3- voltage drops to 0 if the 4 led are connect.
have you ever come across double imaging and ghosting on a Samsung it's a bout 5 years old I have tried putting tape on the ribbon but it still will come back model no 46D5000
That sounds like a timing controller failure from the description.
Any ideas on a fix .with some knowledge and doing at home thanks
derek mcdonald double imaging especially jittering is always a panel failure, any horizontal lines or horizontal effects are always panel related due to tab bond failures in the panel. Tcon issues will generally be loss of video entirely, symmetrical vertical bars and similar. Any localized effects are always panel related because lvds data to tcon are in 8-10-12 bit data streams and will effect the image globally when you get failures outside of the panel... thin vertical and horizontal localized lines... shadowing, ghosting and horizontal jittering is always panel related
Frank Scarano any ideas were to source 1 a panel or what do i need to ask for living in Ireland ty
Honestly panels are the most expensive part in the tv and is generally not cost effective to repair. they tend to cost equal to if not more than the cost of replacing the set
Mine is flashing 6 times?
My lg LEDTv is turning on , showing LG logo and then backlight dissapears . Its the strips, isnt it?
Most definitely the strips or to be honest. One or 2 failed LEDs on the strip.
If you are in the UK I may be able to help with spares
I am still hopeful that the unit will be abandoned and then I can proceed with ripping the panel apart and checking out the lights. I have some strips from a broken screen set. The unit is sitting in my garage awaiting pickup
Thanks
@@allenfleckney5969 Hi I came across your reply to a video and wondered if you could help with backlight leds for Samsung le46c750r2k ? Or possibly repair it for me ???
Hard to jusify spending !,000 dollars on something that only lasts 3 years!
I hear you. Nothing lasts these days. I would really like an OLED set, but it is hard to justify that kind of money on unproven technology. I still like my old Plasma sets they have proven to be reliable for me. I picked up a 4K set for the studio, and got the cheapest one of half decent quality I could find. Only 420.00 so if that only last a few years I won't feel so bad.
12voltvids Was that a Sceptre brand? I've read some good reviews about them.
I feel the same way about "unproven technology". When SSD's came out for computers, a tech for a local hospital I know was raving about how they bring new life into old computers because of their speed. I simply felt they were TOO NEW to fully trust with valuable data. So I have waited a few years to make that leap. Guess I am ABOUT ready, lol!
@@TortureBot you're right. when ssd fails, data impossible to retrieve, as it is aplit over multiple chips. From Hdds you may still recover something. For surface errors, you can skip the area and still get most of files back. Had a WD hdd with bad sectors, I even partitioned it such that empty space was covering the bad areas and could continue using it for non-important backups, i.e. backups of another backup drive.
I am relatively surprised that they run that 195vdc on an LED backlight
Says that's almost as high as an LED lightbulb runs the voltage up to
These are all in series, so the individual voltage drops are quite low. Depending upon how many in the string, about 3 volts.
Well a 50 inch screen has 60 LEDs at 3.5 volts each in series so that's about right.
The reason for the high voltage is the LEDS are in series. This allows low current. If the LEDs were in parallel the voltage would be low, but the current high, and this would require a laager transformer, and heavier wiring. Of course the down side of series LEDs is if one goes bad, you loose the entire strip.
al tv samsung LED is short life not like the sony LED long life
Samsung makes good TVs but if you cheap out then you get what you pay for Sony Samsung are pretty good tv companies. At the moment I have a higher end Vizio witch is not bad but I have more Samsung TVs and haven't had any problems
Depends on the screen used not all Samsung TVs use Samsung screens.
Allen Fleckney I hate to tell you that Sony has its fair share of panel failures where as it has less backlight failures it has plenty of tab bond and internal tcon failures.. and those damn android b,c, and d series Xbr sets have been a nightmare!
Yes they have but not as many as we see of the others. We see 10 a day with backlights issue , but only one a month Sony
yeah.. BL failures arent Sony's weakness. its their main boards.. they are very probematic! Even the D series XBR sets are crapping out left and right! Even the DPS boards are crapping out on those XBR sets
I fix a lot of the LG back light I just by pass the led and the TV will light up only part hard taking out the lcd screen.
If you bypass the backlight you are adding extra voltage to the others meaning they will burn out quicker. Any 3v led from any TVs will work, it doesn't have to be the same strip
I been doing it for 3 years no returns yet
Correct, this will stress others, but at least it gets more life out of the set. If this set ever gets given to me I will be researching further, but the owner said he wants it back, so it went back together.
It may be ok to by pass one 3.5v led even though I don't advise it, but yesterday I did an LG 49 inch that had 12 faulty LEDs , so you can't by pass 40 volts they have to be replaced. These LEDs were advertised as having 10.000 hours. Lucky if they see 1000.
I doubt that many of the LEDs that are advertised as having 20,000 live spans will last beyond 1 - 2000 hours. I am changing more LEDs at my house than the old compact fluorescents that did last 10 years. I have CFLs that are 12 years old and still going strong, but the LEDs seem to only last 2-3 years, and those ones were really expensive too.
Hey my tv light works when I unbluged the whole coord to the bord
Denver Lipp same hir
I have a Samsung UN39FH5000FXZA screen went black with blinking lights. When I disconnect the led plug from the power board I get sound?? Would that be the T-Con board??
Rudy Castro
Did you do the flashlight test.
12voltvids I’ll have to try that again when I connect the hdmi. I’ll try it with that connected to power board and not connect to it
SAMSUNG=TRASH
theyre the best made
BHOLANATH
samsung sucks