Cheapest matching box for the QA75Q9FNA is $350 + $200 for the matching cable. Sadly not worth trying to get going given that it's a gamble and we have no real use for it. Part 2: ruclips.net/user/shortssZl_1bxqeic
I wonder if it would be cheaper for you to buy one in the US and then use a reshipper service. When I search on eBay for One Connect boxes it looks like there are many cheaper options in North America.
@@SirBoden In this particular case I think either the main processor on this board or the original One Connect Box were the source of the failure. The chips run hot and are often benefitted by a reflow or reball. The main processor on here probably has the capability to run standalone, but is cut down in software. Samsung builds the TCON into the SoC in pretty much all of their TVs now, and I'm guessing they've reused that processor here.
The OC box will normally supply the 13V continuously until it gets a signal to switch on the 350v, on Samsung TV's a double flash on the led (every 4 seconds) indicates a T-con Power Management IC error ("T-con PMIC" in the SVC>error logs), either a panel fault or a COF error (Chip On Film)
I wouldn't be surprised if there's no image manipulation or GUI or *anything* on the TV itself. It's probably 100% everything done in the base unit and just communicating LVDS or whatever to the panel itself over that fiber/copper link.
I managed to repair similar failure on a different Samsung TV. It had two flat cables leading from pannel to the electronic board. And you have to block a few of the leads with some tape. It is stupid, but the pannel has sensors to check if a segment of pannel is on. This sensors stop working and the electronics assumes, the pannel is dead. If you block these sensor lines, the TV starts working again.
My best TV suddenly lost its brightness a couple of months ago. It works but the display is so dark that it's absolutely impossible to use it. What should I hunt for? Could that just be a capacitor? Are the capacitors discharged after 2 or 3 months? Many thanks.
Australians dumpsters: 3d printers, high end TVs, bench drills, soldering stations, and other magic equipment! high end tech!!! Its worth to pay rent to be in such place - content from this dungeon will be enough for 1yr of making YT vids.
They also throw bars of pure gold into the trash. The bars get dirty or get a hairline scratch, replace them with new gold bars and throw the old ones away. Lock the dumpster to make sure the gold bars go into a landfill. Finance the new gold bars on your credit card.
Might be attempting to communicate with the base unit, to retrieve info and connect to a data stream. thus the red flash to say screen powered up, but failed to communicate. You will probably find getting the matching box will fully power it up, as likely the small controller on the display side does not actually do more than supervisory functions, it handles power on, and handles remote receiver and push buttons, but the main application processor, that can actually display on the screen, is down the cable, and this one only handles power, backlight control alone. Screen on at least means it is functional though. time to find the cable and base unit, and put the thing back together for either home use, or as a lab display, will make a great monitor there.
Quite possible. Chat GPT says the box does contain the main processor, but Grok says is does not. The box and cable don't seem to be cheap, so it's a gamble.
@@EEVblog wait till new year, when there likely will be sales on, after all it is just an itch to scratch, there will be others in there at some point.
@@EEVblogcan you transplant a power supply and main board / tcon board from another set of the same resolution? I’ve done it a few times with hit and miss results.
I'm starting to think this too. The 13V is definitely marked as an output on the PSU board, so unless the PSU is dead the 13V should be there. Not that it matters for the purposes of seeing if something boots up, it's just for the fibre optic receivers in the cable.
@@EEVblog Often when these TV boards fail it is the diode or the (49pf?) inductor on the powerboard that provides the 13v (~12.7v on some TV if I remember correctly) turn on signal. I have had the same issue several times as well. This circuit basically tells the TV to turn on the backlight etc. Symptoms are, TV turns on for a few seconds, light flashes red, screen may turn white and then backlight turns off again. You can hold a flashlight to the screen and see the no signal image really faintly and the LCD has a blackish blue tint (kinda looks like yours is doing the same). Switched the diode and inductor for a few cents, and it was good as new. Might also be one of the caps related to that circuit if the inductor or diode is fine. These TVs often build up a ton of heat inside, slow cooking the electrolytics.
I would've thrown a blanket over the front to protect the coating on the screen and dampen pressure points. It's painful to watch the panel directly on concrete.
In my limited experience trying to repair Samsung TVs, there are a few checks and balances that occur when the TV is powered on. This includes what i imagine is a voltage or current check of the backlight LEDs that are in series (3 LEDs) parallel. In my case, one of those SMD LEDs had broken off, so that when then 270v was applied to the series LEDs and it fell about 9v short, the TV immediately turned off.
I appreciate you mentioning Elecami Wolf and his channel. You referred to him back in the video about self-healing capacitors and I've been watching his videos ever since.
When you placed the TV on the ground, leaning against the wall, I would've put a couple of pieces of cloth in between the TV and the ground and in between it and the wall in order to avoid any potential scratches. 👍
The 350V is just the rectified mains, so it's likely going to take in a wide range of voltages from 200-250V or so to whatever it comes out of. It's a switching supply so it's not too fussy about the input voltage (switching supplies convert the incoming AC to DC first). I suspect it's just being tapped off the main rectifier of the box. The other voltages are probably Vamp - analog voltage to speaker amplifiers, PWM to control the backlight brightness (the power supply almost certainly has a LED driver for the backlight, so it needs a PWM signal to control the brightness). The error code is likely something along the lines of not receiving a signal from the box for the display - the one connect box is basically all the processing logic of the TV - the screen is just taking a fixed video signal and putting it on the screen. All the signal conversion, scaling, image processing, etc are likely being done by the box. I would guess there is a low voltage reverse signal cable to send button presses and IR codes back to the box to handle the actual remote control operations. It's blinking a light saying it's not receiving a video signal from the box
Pry up the corner and peep inside to find the steel wire triangle ring end. Use a steel hook to catch the ring end and pull out the steel wire, you may need to twist the ring end to disengage the frame lock catch. Or use a very strong thin metal square rod to run thru the ring hole, then slide the steel wire out. No more un-click each every catch.
After fighting to get inside one of these and seeing the lock wires I figure next time I could lift one corner then reach in and grab the wire and pull it out. One day I may have another to test that theory
I took apart one of Samsung's curved TV's maybe 8 years ago, it had the same system with the wire. What a nightmare to get apart without damaging the case. I'm sure if you have the right disassembly-tool it's easy enough, but as always, there were never designed to be taken apart again.
I've purchased a Milwaukee oscillatory tool with plans to cut an opening big enough to access the power supply board on a large screen TV I dumpster dived ... it tries to power up, but the symptoms match those for a bad PSU switching PS cap set ....
If you see this comment, the back light may have a few bad LEDs. The over voltage protection is preventing the tv from turning on due to improper load of the LEDs.
Dave, you're supposed to pull the steel cables out from the top corners (there are small hooking points on each cable), and the back cover will come off naturally :D . Next time you will know
I don't have a magic dumpster room like Dave. Early December I was out for a walk. I saw a monitor by the side of the road. No sign of a cracked screen so I brought it home. It is a ASUS 22" LCD monitor with HDMI, DVI, VGA, and audio inputs. I powered it up and fed it a signal via the HDMI input. The screen looks great. Nothing wrong with it. Nice early Christmas present to myself. :)
@EEVblog Thanks David for your great content, we also thank you for your no B.S. plain speaking Oz language😄😄😄😄 You call a spade a spade, we LOVE THIS. We are new subscribers to your channel, and wish aĺl your end A Verry Merry Christmas And Happy Prosperous New Year. Love You Dave. Warmest Regards Wayne, Nina & Barbara (Ipswich, Suffolk, UK) 🫶🫶🫶🫶🫶🫶🫶❤️❤️❤️❤️❤️❌️❌️❌️❌️🫡🫡🫡🫡🫡😄😄😄😄😄
a cracked screen has nothing to do with the quality of the electronics... every manufacturer has some issues but you can easily check consumer reports or reviews.
The red flashing led indicates the open cell is faulty - a very common failure. Unlikely to be able to source a replacement. Be careful removing the back cover at the bottom edge, because that's often where the open cell connectors and ribbons are located, and they are incredibly fragile. A screwdriver will easily damage these components. The sides and top edges are usually clear of delicate electronics.
@EEVblog the open cell is the LCD screen that sits over the back light. When combined, it's called a "panel". You can sometimes replace an open cell independently of the backlight (if you can order the part). (Edit: replacing an open cell isn't really practical for individuals, because it requires suction tools, adhesive tape, and a very fragile LCD component. But a repair agent should be able to do it. It just comes down to cost, and whether it's worth it. Also, without the One Connect box, it's pretty useless. From a salvage/reuse perspective, you may be able to remove the LCD entirely and use the backlight as a light panel.)
@@EEVblog I think he means LED illumination 'cell", but I could be wrong. Usually those are strips with LEDs and a fat lens mounted ever 100 to 200 mm or so on the strips (you've seen them) ...
If you have a Samsung remote and the TV has an infrared receiver, press either INFO MENU MUTE POWER or MUTE 1 8 2 POWER in sequence and see if a service menu appears. Do so when the TV is in standby.
@EEVblog Love you David, you're one bonzer bloke. Many Thanks For Your Valued Content. Merry Christmas & Happy Prosperous 2025 mate👍👍👍👍👍 Warmest Regards Wayne, Nina, Barbara & Archie the budgie (Ipswich, Suffolk, UK) 👍👍👍👍👍🫡🫡🫡🫡🫡❤️❤️❤️❤️🫂🫂🫂🫂🫂🤝🤝🤝🤝🤝🇬🇧🇬🇧🇬🇧🇬🇧🇬🇧🇭🇲🇭🇲🇭🇲🇭🇲🇭🇲😊😊😊😊😊😊😊🎄🎄🎄🎄🎄⛄️⛄️⛄️⛄️⛄️
I'd be suspicious of the role of PS_ON. I assume this is a soft start from the control box to turn it on and off, maybe it needs to be asserted for the control board to boot up?
There’s a mystery here: “Why” has the signal box been separated from the panel? They’re not any good individually, and probably a huge nuisance to buy separately.The quality of manufacture seems first class, yet it’s down in the dumpster after 6 years. You wish there was a service depot to fix it, but it’s so huge and fragile it’s special delivery in a big truck just to have a boo. The practical reality of these things is extremely disappointing.
An automotive trim clip tool would possibly work there, the sort like a pair of inverted pliers - squeeze the handles and the jaws push apart. The jaws are very thin and are designed to slip between door cards and door panels - a lot like you have here. Front of that screen looks scratched to buggery though :(
Hi Dave If you remove the cable from the main to the power supply board the set should give you brightness and a logo that says one connect box. It forces the set on. If you get no brightness I would say that the display panel is bad replacing the leds on this model is not a great idea. If it comes up with a picture with one connect instructions you can go further otherwise junk it
To remove the back, Samsung provide a tool, but I've found a standard sharpie does the job, just open the first clip then wedge the sharpie in and drag it around the edge and the clips pop off without prying against the metal chassis.. NOT along the bottom though, the panel hinges off after going up the edges and along the top. Sometimes it can snap the corner off the back panel but more often than not it works fine.
Samsung has stopped using screws as much as possible. I replaced the main board (and PSU, and TCON, it's all one board!) in one not too long ago. The back was clipped on and the board was clipped in. So were the speakers and the little LED/button board. I don't think there was one screw in that TV!
I did the same not a single screw. With the the 2 main boards You slide to the side you just left one side up and slide. Same with the speakers they were connected with blue isolator pieces of rubber. Kind of like how some PC fans can be mounted. Also even though the TV was less than five years old the clips are very brittle. It seems like the plastic is 30 years old. I think the way that it clips on has something to do with being able to use lower quality cheaper plastics the best way I can describe it is that it's made from the same plastic you would use to make records from back in the day. I think small edge clips that were used to seeing would not be strong enough or easily snap considering the plastic that is used.
This is actually an interesting technical achievement. Munro Live should do a teardown of one sometime (they're a huge fan of removing threaded fasteners where possible) - the lack of threaded fasteners is a huge productivity advantage in manufacturing environments because it greatly reduces cycle time and assembly steps.
it also makes repair and maintaining worse. of course takt is important for manufacturing, but come on. cheap shitty clips are just worse in every regard.
@@vegasu9418 not when to have to repair 30 plus a day during a recall. 20 seconds to set up tables, 30 seconds to pop of the back. 30 seconds to unclip all cables and FFCs and 2 seconds to slide the board out. No screws is fantastic.
Just hook in on the backlight, if your narrative is to check screen fidelity for cracks as you ain't gonna do jack systemwide without the OC mothership.. This puppy needs to phone home..
Got to give it to sam-dung for being the Apple of TVs and making proprietary crap that can't be fixed. Especially on a high-end device.. Kind of ironic that somebody would buy this only to put it on a stand... The whole point of one connect is to make it flatter to put on it on a wall!
Saw a video on someone repairing tvs, and they said do not buy samsung now, you cannot repair them Companies are getting rid of peoples right to repair They are making electronics so complicated so the public cannot repair them, even qualified people like you would find it hard, and you would not be able to buy the parts. Its about stopping people repairing stuff, right to repair is getting harder, and companies do not want it
I don't get why all the power electronics isn't in a separate box. Then simply have a ribbon cable go to the screen with a power bus. The power and signal boards would run cooler and be away from the backlight heat. Not many people hang their tellies on walls when they're that big...
These modern Samsung TV's are absolutely abysmal. The displays look stellar in the store but they're more useless than a rusty door hinge at anything "smart" and last for a couple of years before problems start appearing. 2009 Samsung TV we have is still kicking like new.
@@TassieLorenzo I am a repair tech and every tv breaks at some point. I would Suggest you really check out the customer service that others have experienced with the brands before committing to any brand. I personally own 4 OLED LGs. B3 77 C2 42 G4 65 and GQ900 48 thats my opinion.
Yeah. Have had 2 Samsung SSDs die. Have a Samsung Odyssey G9 Neo which is half-dead after just 3 years. Somewhat missed it enough to pickup a new OLED G9 on black friday deals, but honestly I'm not expecting it to last all that long either. Sadly everything else on the market right now is pretty "meh" so I wasn't happy with any alternatives either, hopefully in a couple of years there'll be much better options. It just sucks knowing that Samsung seem to be one of the few that make really great stuff on paper, but the quality just doesn't seem to be there. Also the fact that they supply so many components to other brands as well, such as panels, memory, etc.
It's a shame the oneconnect boxes are so expensive on ebay, i'm sure a lot of perfectly good ones get thrown in the bin after people break their display panels. I like the oneconnect concept of separating the inputs and processing from the panel, but it sucks that it's completely propriatery. Imagine if you could mix and match them, buy a completely dumb panel and add whatever input/signal processor you want, change from tizen to android to linux or whatever.. Maybe the EU should get on that!
I have an 85" HiSense. It's 115ish pounds. It absolutely needs two people to move it around/adjust. That said, the panel retention Samsung used is very dumb. Who thought that was a good idea?
most likely display faulty, you can block ckv signals if you lucky it will work perfectly if not some lines on screen persist, anyway, Samsung tvs has no error codes. Disconnect some flat flexi cables between quarters of screen to find out where is the problem or could be protective diode faulty or simply shorted cap on driver boards
It is also possible to pull out the steel wires on the edge... a common problem on the samsungs is some sort of error signal coming from the display. Disconnect both flat cables to the display and try repower, when you hear the starting sound it could be this problem. A fix is to tape some contacts on the display cables....
The board thinks there is a panel fault. You can sometimes fudge these by using kapton tape on the flat flex, but I can tell you they ALL develop this fault eventually and end up in the bin. I would not buy another Samsung the life is 5 years if you're lucky and then typically this happens.
EE here: We are too much alike, working on a free LCD recently too (guess you can classify it as a dumpster one). In my case looks to be a more simple case of a TCON. (happy vertical line pattern)
Modern LCD panels are throw away consumables, they're not like the CRT TVs of old that are more easily repaired as long as the tube is good. LCD panels aren't as strong either.
I would try to connect this display to the electronics of the other , bigger tv with the broken panel by injecting directly the EDP or LVDS signals to the screen and using the backlight power supply of the smaller one. I would also check the enabling signals coming from the logic board to the power supply to check if the backlight flash is due to an electric control or to a failure of the backlight, that triggers the protection feature.
I took my old workplace big tv that overheated. I already know the issue and fix. They just wanted to replace it and gave it to me for free. They had a custom wooden box around the tv, which is why it overheated. All I had to do is replace the motherboard, which was worth it.
those crappy tvs came with a crappy LCD where you need isolate some pins to get some video and find the troubleshooting of it, which is mostly shorted lcd ics in the ribbon.
I watched this on my $400 BENQ projector in the living room, which casts a 12’+ picture, yet weighs just a couple pounds and is approximately the size and weight of a PlayStation console. The disadvantages are: I had to crawl around in the attic to install another outlet and run long signal wires, so I have to own the house. But the advantage is a much smaller cheaper unit to service/replace. Also it has zero proprietary wire-up boxes or novel power arrangements. Mine has the 3D glasses capability, which means it can also do that screen-sharing trick the PlayStation can do. These monster flat screen tvs were a dream for decades now (famously: Elvis Presley’s multiple inset tvs in his living room). The reality, as with Presley, is a near-insurmountable service headache. I liked the BENQ so much I put in another one in the rumpus room downstairs!
There are ultra short throw projectors if you don't want to or can't mount it to the ceiling. They sit below the screen, less than a foot away from the wall. The downside is they require a special screen that will cost over $1000.
I’m amazed they don’t have standard connections on the back for future use as a tv and not an advertising screen. They could make money from selling it on.
I have repaired this TV many times and the problem is that the current sense circuit for the Backlights is being triggered to power down. This is caused by any number of LEDs on the LED strips that are shorted out internally. This causes an overcurrent situation and the mainboard will flash the red power good indicator several times before sending the PSU back to standby mode. Its not worth it to replace individual LEDs that have gone bat but instead we replace the entire set of strips and Bob's y our uncle. Sometimes an LED will blow open, in which case you may not get any backlight or you will get partial backlight coverage from the still working LED strips. There is no point in trying another PSU, Mainboard, or TCON board until you strip the chassis down to the the bare insides to verify each LED strip. New LED strips are best to order from AliExpress using the part number written directly on the silkscreen of the LED strips themselves. A generic search for the correct parts using the TV's Model Number will only lead to confusion and likely obtaining the wrong set of LED strips. Best of luck. This one IS a fixer!
One of the problems with these tvs is that if the buttons on the remote gets stuck down as in the power button the tv h cycle on and off as many times as the remote was pressed. It happed to my Samsung tv and it kept turning on and off like that. Even with the power disconnected it still remembers how many times the remote was pressed and no way to reset it. You have to let the tv cycle on and off until its done and it will work fine after that (it took many hours)
Oooh it connects like my odyssey ark. Last week I learned my niece also has a samsung that connects to the same sort of box. I got access to two of the things! 😅
Looks like you have an overcurrent situation through the LEDs caused by some of them shorting out. Had that on a 70" tv of mine. Put a few high wattage 8ohm resistors in series which gave me a few more years of viewing time although the picture was not equally bright in all areas.
My Samsung TV also died in a similar fashion. One day I was watching it and then suddenly it just went off by itself and would just flash the red light. Apparently you can fix it with some tape on the Flex cable forming from the panel but I never tried and just got it replaced under warranty
Man, are there courses in mechanical engineering teaching how to design annoying clips? The idea with the cable is great but it should have a screw to de-tension the cable to loosen all clips at once. We thoroughly need right to repair legislation.
Good were the days when things were held together by bolts and screws. These plastic clip affairs are always a gamble. Patience and frustration avoidance are the rules of the game.
You have an unbroken panel. After watching the short, I still think it might be worth it to get a TV that has a broken panel that uses the same panel you have in here. Do a panel transplant. I own a 75" QLED TV and love the image quality. The TV with the broken panel shouldn't set you back more than a few dollars if you can pick it up locally. Even for curiosity on the strange art the back panel is showing you when you light it up separately, I would try and get the panel in another TV.
Samsung LCD matrix some lines gets faulty and this talks to main board to shut down. You can put tape on ribbon cable tracks which can bypass protection .
Cheapest matching box for the QA75Q9FNA is $350 + $200 for the matching cable. Sadly not worth trying to get going given that it's a gamble and we have no real use for it.
Part 2: ruclips.net/user/shortssZl_1bxqeic
I wonder if it would be cheaper for you to buy one in the US and then use a reshipper service. When I search on eBay for One Connect boxes it looks like there are many cheaper options in North America.
I’d salvage the useful parts and bin the rest.
@@SirBoden In this particular case I think either the main processor on this board or the original One Connect Box were the source of the failure. The chips run hot and are often benefitted by a reflow or reball. The main processor on here probably has the capability to run standalone, but is cut down in software. Samsung builds the TCON into the SoC in pretty much all of their TVs now, and I'm guessing they've reused that processor here.
@@EEVblog now that is a work of art dave could sell that maybe the board not sure
Could you splice the boards from the 86" with the broken screen into it to make it into a "normal" TV?
The OC box will normally supply the 13V continuously until it gets a signal to switch on the 350v,
on Samsung TV's a double flash on the led (every 4 seconds) indicates a T-con Power Management IC error ("T-con PMIC" in the SVC>error logs), either a panel fault or a COF error (Chip On Film)
I always love how these tvs have their circuit boards carefully annotated.
I wouldn't be surprised if there's no image manipulation or GUI or *anything* on the TV itself. It's probably 100% everything done in the base unit and just communicating LVDS or whatever to the panel itself over that fiber/copper link.
I managed to repair similar failure on a different Samsung TV. It had two flat cables leading from pannel to the electronic board. And you have to block a few of the leads with some tape. It is stupid, but the pannel has sensors to check if a segment of pannel is on. This sensors stop working and the electronics assumes, the pannel is dead. If you block these sensor lines, the TV starts working again.
hmm, never would have imagined it.
So they use panel function sensors that are less reliable than the panel they're supposed to monitor the function of?
My best TV suddenly lost its brightness a couple of months ago. It works but the display is so dark that it's absolutely impossible to use it.
What should I hunt for? Could that just be a capacitor? Are the capacitors discharged after 2 or 3 months?
Many thanks.
@leoa4c shine a torch if picture is visible, it's most likely led, it can be replaced.
@@yoppindia Even without a torch, a picture is visible. It's as if the back light went from 100% to about 5%.
Australians dumpsters: 3d printers, high end TVs, bench drills, soldering stations, and other magic equipment! high end tech!!! Its worth to pay rent to be in such place - content from this dungeon will be enough for 1yr of making YT vids.
Electronics dumpster at my german shopping mall:
10-15 year old computers and 7-10 year old TV's 😢
They also throw bars of pure gold into the trash. The bars get dirty or get a hairline scratch, replace them with new gold bars and throw the old ones away. Lock the dumpster to make sure the gold bars go into a landfill. Finance the new gold bars on your credit card.
Yep!
Dumpster here in Brazil: old broken flip phones and smashed CRT TV's
Dumpster here in SA 🇿🇦 just compost!😂 Plastic goes to the waste pickers, metal to the scrap dealers and the rest is just organic!!😂
Might be attempting to communicate with the base unit, to retrieve info and connect to a data stream. thus the red flash to say screen powered up, but failed to communicate. You will probably find getting the matching box will fully power it up, as likely the small controller on the display side does not actually do more than supervisory functions, it handles power on, and handles remote receiver and push buttons, but the main application processor, that can actually display on the screen, is down the cable, and this one only handles power, backlight control alone. Screen on at least means it is functional though. time to find the cable and base unit, and put the thing back together for either home use, or as a lab display, will make a great monitor there.
Quite possible. Chat GPT says the box does contain the main processor, but Grok says is does not. The box and cable don't seem to be cheap, so it's a gamble.
Cheapest I can find is $479 just for the box, another few hundred for the cable.
@@EEVblog wait till new year, when there likely will be sales on, after all it is just an itch to scratch, there will be others in there at some point.
@@EEVblog Returns policy? Don't you have good consumer rights in Aus?
@@EEVblogcan you transplant a power supply and main board / tcon board from another set of the same resolution? I’ve done it a few times with hit and miss results.
I'd be surprised if this didn't need to see some sort of comms to stay powered up - did you check that the 13V supply was coming up when powered?
I'm starting to think this too. The 13V is definitely marked as an output on the PSU board, so unless the PSU is dead the 13V should be there. Not that it matters for the purposes of seeing if something boots up, it's just for the fibre optic receivers in the cable.
@@EEVblog Often when these TV boards fail it is the diode or the (49pf?) inductor on the powerboard that provides the 13v (~12.7v on some TV if I remember correctly) turn on signal. I have had the same issue several times as well. This circuit basically tells the TV to turn on the backlight etc.
Symptoms are, TV turns on for a few seconds, light flashes red, screen may turn white and then backlight turns off again. You can hold a flashlight to the screen and see the no signal image really faintly and the LCD has a blackish blue tint (kinda looks like yours is doing the same). Switched the diode and inductor for a few cents, and it was good as new.
Might also be one of the caps related to that circuit if the inductor or diode is fine. These TVs often build up a ton of heat inside, slow cooking the electrolytics.
I would've thrown a blanket over the front to protect the coating on the screen and dampen pressure points. It's painful to watch the panel directly on concrete.
Dave is so heartless.
he gets lots of such beasty TV for free in the dumpster, not like us mortals.
"She'll be right, mate! No wuckers!" (my best Dave impression)
OMG I've opened these before. Watching you snap the back panel off, I'm screaming noo, pull the wire!
A bed makes a great workbench for large TVs and other things.
I never thought of that......................Mind u,you have to carry the damm things upstairs first !
@@mikek8249 Or to the dunge... er, basement.
In my limited experience trying to repair Samsung TVs, there are a few checks and balances that occur when the TV is powered on. This includes what i imagine is a voltage or current check of the backlight LEDs that are in series (3 LEDs) parallel. In my case, one of those SMD LEDs had broken off, so that when then 270v was applied to the series LEDs and it fell about 9v short, the TV immediately turned off.
Love the dumpster vids!!! Hope always!!!
Hey I undescribed 😊
One of my favorite segments next to mailbag.
I appreciate you mentioning Elecami Wolf and his channel. You referred to him back in the video about self-healing capacitors and I've been watching his videos ever since.
Knowing Samsung, it requires a handshake to fully turn on, which means it's worthless without the box.
B350v is the PFC DC output from the PSU, its usually 380v in the UK, and VAMP is the power for the audio amplifiers.
It requires control signals from the one connect to power up properly. It perform like that to protect the panel.
When you placed the TV on the ground, leaning against the wall, I would've put a couple of pieces of cloth in between the TV and the ground and in between it and the wall in order to avoid any potential scratches. 👍
The 350V is just the rectified mains, so it's likely going to take in a wide range of voltages from 200-250V or so to whatever it comes out of. It's a switching supply so it's not too fussy about the input voltage (switching supplies convert the incoming AC to DC first). I suspect it's just being tapped off the main rectifier of the box. The other voltages are probably Vamp - analog voltage to speaker amplifiers, PWM to control the backlight brightness (the power supply almost certainly has a LED driver for the backlight, so it needs a PWM signal to control the brightness). The error code is likely something along the lines of not receiving a signal from the box for the display - the one connect box is basically all the processing logic of the TV - the screen is just taking a fixed video signal and putting it on the screen. All the signal conversion, scaling, image processing, etc are likely being done by the box. I would guess there is a low voltage reverse signal cable to send button presses and IR codes back to the box to handle the actual remote control operations. It's blinking a light saying it's not receiving a video signal from the box
Pry up the corner and peep inside to find the steel wire triangle ring end. Use a steel hook to catch the ring end and pull out the steel wire, you may need to twist the ring end to disengage the frame lock catch. Or use a very strong thin metal square rod to run thru the ring hole, then slide the steel wire out. No more un-click each every catch.
So, do you then reinstall the wire and pop the clips back over it to reinstall the back?
@mavamQ correct
After fighting to get inside one of these and seeing the lock wires I figure next time I could lift one corner then reach in and grab the wire and pull it out. One day I may have another to test that theory
I took apart one of Samsung's curved TV's maybe 8 years ago, it had the same system with the wire. What a nightmare to get apart without damaging the case. I'm sure if you have the right disassembly-tool it's easy enough, but as always, there were never designed to be taken apart again.
I've purchased a Milwaukee oscillatory tool with plans to cut an opening big enough to access the power supply board on a large screen TV I dumpster dived ... it tries to power up, but the symptoms match those for a bad PSU switching PS cap set ....
It's not going to do anything without the one connect box. Maybe see if its in the dumpster.
Dave looked for it when he found the TV. He couldn't find it. Maybe it was bagged.
If you see this comment, the back light may have a few bad LEDs. The over voltage protection is preventing the tv from turning on due to improper load of the LEDs.
This reminds me of the phrase "there is no such thing as a free puppy."
Dave, you're supposed to pull the steel cables out from the top corners (there are small hooking points on each cable), and the back cover will come off naturally :D . Next time you will know
I don't have a magic dumpster room like Dave. Early December I was out for a walk. I saw a monitor by the side of the road. No sign of a cracked screen so I brought it home. It is a ASUS 22" LCD monitor with HDMI, DVI, VGA, and audio inputs. I powered it up and fed it a signal via the HDMI input. The screen looks great. Nothing wrong with it. Nice early Christmas present to myself. :)
@EEVblog
Thanks David for your great content, we also thank you for your no B.S. plain speaking Oz language😄😄😄😄
You call a spade a spade, we LOVE THIS.
We are new subscribers to your channel, and wish aĺl your end A Verry Merry Christmas And Happy Prosperous New Year.
Love You Dave.
Warmest Regards
Wayne, Nina & Barbara (Ipswich, Suffolk, UK)
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The language he uses is not how everyone talks here in au. That's just Dave ;-)
@g4z-kb7ct
Yeah, we know, but we still love Dave😉👍
Many Thanks For Your Comment.
Merry Christmas & Keep Safe Sir/Madam.
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So many dumpster Samsungs. I never have faith they'll work.
That's why I steer clear of Samsung. It's all junk.
a cracked screen has nothing to do with the quality of the electronics... every manufacturer has some issues but you can easily check consumer reports or reviews.
And here we see a SamSuckIT in it's natural habitat - the dumpster. Please don't tap on the glass
Lots of samsung products last one year tops, classic case of planned obsolescence brand.
@Melamamoduro Don't know why my parents keep buying that junk. My EKO TV from Big W has lasted over 3 years. 😂
It is not just the screws that are expensive. It is made not to be cheaply repairable.
I worked on a cheap black Friday Samsung 70 inch to replace backlights and it had the same system. Such a pain in the rear.
The red flashing led indicates the open cell is faulty - a very common failure. Unlikely to be able to source a replacement.
Be careful removing the back cover at the bottom edge, because that's often where the open cell connectors and ribbons are located, and they are incredibly fragile. A screwdriver will easily damage these components. The sides and top edges are usually clear of delicate electronics.
What is an "open cell"?
@EEVblog the open cell is the LCD screen that sits over the back light. When combined, it's called a "panel". You can sometimes replace an open cell independently of the backlight (if you can order the part).
(Edit: replacing an open cell isn't really practical for individuals, because it requires suction tools, adhesive tape, and a very fragile LCD component. But a repair agent should be able to do it. It just comes down to cost, and whether it's worth it. Also, without the One Connect box, it's pretty useless. From a salvage/reuse perspective, you may be able to remove the LCD entirely and use the backlight as a light panel.)
@@EEVblog I think he means LED illumination 'cell", but I could be wrong. Usually those are strips with LEDs and a fat lens mounted ever 100 to 200 mm or so on the strips (you've seen them) ...
If you have a Samsung remote and the TV has an infrared receiver, press either INFO MENU MUTE POWER or MUTE 1 8 2 POWER in sequence and see if a service menu appears. Do so when the TV is in standby.
@EEVblog
Love you David, you're one bonzer bloke.
Many Thanks For Your Valued Content.
Merry Christmas & Happy Prosperous 2025 mate👍👍👍👍👍
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I'd be suspicious of the role of PS_ON. I assume this is a soft start from the control box to turn it on and off, maybe it needs to be asserted for the control board to boot up?
There’s a mystery here: “Why” has the signal box been separated from the panel? They’re not any good individually, and probably a huge nuisance to buy separately.The quality of manufacture seems first class, yet it’s down in the dumpster after 6 years. You wish there was a service depot to fix it, but it’s so huge and fragile it’s special delivery in a big truck just to have a boo. The practical reality of these things is extremely disappointing.
Siemens/Bosch uses the angled heat sinks on their induction panels/hobs
An automotive trim clip tool would possibly work there, the sort like a pair of inverted pliers - squeeze the handles and the jaws push apart. The jaws are very thin and are designed to slip between door cards and door panels - a lot like you have here.
Front of that screen looks scratched to buggery though :(
Hi Dave If you remove the cable from the main to the power supply board the set should give you brightness and a logo
that says one connect box. It forces the set on. If you get no brightness I would say that the display panel is bad replacing the leds on this model is not a great idea. If it comes up with a picture with one connect instructions you can go further otherwise junk it
Nice AOC minitor down there!
Another fine dumpster find.
Never go to the dumpster without camera and tripod !
To remove the back, Samsung provide a tool, but I've found a standard sharpie does the job, just open the first clip then wedge the sharpie in and drag it around the edge and the clips pop off without prying against the metal chassis.. NOT along the bottom though, the panel hinges off after going up the edges and along the top. Sometimes it can snap the corner off the back panel but more often than not it works fine.
Samsung has stopped using screws as much as possible. I replaced the main board (and PSU, and TCON, it's all one board!) in one not too long ago. The back was clipped on and the board was clipped in. So were the speakers and the little LED/button board. I don't think there was one screw in that TV!
New oleds s90D on wards have one grounding screw on the power board thats it
I did the same not a single screw. With the the 2 main boards You slide to the side you just left one side up and slide. Same with the speakers they were connected with blue isolator pieces of rubber. Kind of like how some PC fans can be mounted. Also even though the TV was less than five years old the clips are very brittle. It seems like the plastic is 30 years old. I think the way that it clips on has something to do with being able to use lower quality cheaper plastics the best way I can describe it is that it's made from the same plastic you would use to make records from back in the day. I think small edge clips that were used to seeing would not be strong enough or easily snap considering the plastic that is used.
This is actually an interesting technical achievement. Munro Live should do a teardown of one sometime (they're a huge fan of removing threaded fasteners where possible) - the lack of threaded fasteners is a huge productivity advantage in manufacturing environments because it greatly reduces cycle time and assembly steps.
it also makes repair and maintaining worse. of course takt is important for manufacturing, but come on. cheap shitty clips are just worse in every regard.
@@vegasu9418 not when to have to repair 30 plus a day during a recall. 20 seconds to set up tables, 30 seconds to pop of the back. 30 seconds to unclip all cables and FFCs and 2 seconds to slide the board out. No screws is fantastic.
I just replaced some caps on a 43 inch Samsung that was snapped together like that. What a PITA!
Just hook in on the backlight, if your narrative is to check screen fidelity for cracks as you ain't gonna do jack systemwide without the OC mothership..
This puppy needs to phone home..
I just saved one. Cost zero for the telly, £15 for the LEDs, half hour job. Bonzer
And thats why I don't fix TVs anymore.
Got to give it to sam-dung for being the Apple of TVs and making proprietary crap that can't be fixed. Especially on a high-end device.. Kind of ironic that somebody would buy this only to put it on a stand... The whole point of one connect is to make it flatter to put on it on a wall!
Nice to see Samsung calls for a 250V rated fuse for a 350V input ;)
Saw a video on someone repairing tvs, and they said do not buy samsung now, you cannot repair them
Companies are getting rid of peoples right to repair
They are making electronics so complicated so the public cannot repair them, even qualified people like you would find it hard, and you would not be able to buy the parts.
Its about stopping people repairing stuff, right to repair is getting harder, and companies do not want it
Clearly a TV that is designed to avoid being repaired. A trend that is becoming widespread for absolutely everything...
I don't get why all the power electronics isn't in a separate box.
Then simply have a ribbon cable go to the screen with a power bus.
The power and signal boards would run cooler and be away from the backlight heat.
Not many people hang their tellies on walls when they're that big...
These modern Samsung TV's are absolutely abysmal. The displays look stellar in the store but they're more useless than a rusty door hinge at anything "smart" and last for a couple of years before problems start appearing. 2009 Samsung TV we have is still kicking like new.
Oh dear. 🙁 Thanks for the heads-up! Would you recommend LG or Sony instead, or one of the Chinese brands like Hisense, or something else?
@@TassieLorenzo
LG is Samsung. Get a Sony Bravia or Panasonic mini LED
@@pyeltd.5457LG is Samsung? Nope. What you mean?
@@TassieLorenzo I am a repair tech and every tv breaks at some point. I would Suggest you really check out the customer service that others have experienced with the brands before committing to any brand. I personally own 4 OLED LGs. B3 77 C2 42 G4 65 and GQ900 48 thats my opinion.
Yeah. Have had 2 Samsung SSDs die. Have a Samsung Odyssey G9 Neo which is half-dead after just 3 years. Somewhat missed it enough to pickup a new OLED G9 on black friday deals, but honestly I'm not expecting it to last all that long either. Sadly everything else on the market right now is pretty "meh" so I wasn't happy with any alternatives either, hopefully in a couple of years there'll be much better options.
It just sucks knowing that Samsung seem to be one of the few that make really great stuff on paper, but the quality just doesn't seem to be there. Also the fact that they supply so many components to other brands as well, such as panels, memory, etc.
Dave,this episode might be the start of a new channel: eevBOOM!
Cheers!
It's a shame the oneconnect boxes are so expensive on ebay, i'm sure a lot of perfectly good ones get thrown in the bin after people break their display panels. I like the oneconnect concept of separating the inputs and processing from the panel, but it sucks that it's completely propriatery. Imagine if you could mix and match them, buy a completely dumb panel and add whatever input/signal processor you want, change from tizen to android to linux or whatever.. Maybe the EU should get on that!
Dave's favorite hobby! Dumpster Diving in rich man's neighborhood!
I have an 85" HiSense. It's 115ish pounds. It absolutely needs two people to move it around/adjust. That said, the panel retention Samsung used is very dumb. Who thought that was a good idea?
most likely display faulty, you can block ckv signals if you lucky it will work perfectly if not some lines on screen persist, anyway, Samsung tvs has no error codes. Disconnect some flat flexi cables between quarters of screen to find out where is the problem or could be protective diode faulty or simply shorted cap on driver boards
It is also possible to pull out the steel wires on the edge... a common problem on the samsungs is some sort of error signal coming from the display. Disconnect both flat cables to the display and try repower, when you hear the starting sound it could be this problem. A fix is to tape some contacts on the display cables....
The board thinks there is a panel fault. You can sometimes fudge these by using kapton tape on the flat flex, but I can tell you they ALL develop this fault eventually and end up in the bin. I would not buy another Samsung the life is 5 years if you're lucky and then typically this happens.
That's one expensive Door sized tv you got there
EE here: We are too much alike, working on a free LCD recently too (guess you can classify it as a dumpster one). In my case looks to be a more simple case of a TCON. (happy vertical line pattern)
looks like time to salvage what you can Dave.
Modern LCD panels are throw away consumables, they're not like the CRT TVs of old that are more easily repaired as long as the tube is good. LCD panels aren't as strong either.
thanks for the video. I won't buy any POS like this.
they advertise this One Connect BS as though it's a good thing.
I like how the PSU board is annotated though. That's very unexpected to see these days.
Samsung televisions in general have changed over the years. They are difficult to service nowadays. Too much of the display is glued together.
I would try to connect this display to the electronics of the other , bigger tv with the broken panel by injecting directly the EDP or LVDS signals to the screen and using the backlight power supply of the smaller one.
I would also check the enabling signals coming from the logic board to the power supply to check if the backlight flash is due to an electric control or to a failure of the backlight, that triggers the protection feature.
I took my old workplace big tv that overheated. I already know the issue and fix. They just wanted to replace it and gave it to me for free. They had a custom wooden box around the tv, which is why it overheated. All I had to do is replace the motherboard, which was worth it.
those crappy tvs came with a crappy LCD where you need isolate some pins to get some video and find the troubleshooting of it, which is mostly shorted lcd ics in the ribbon.
You are apparently, not supposed to repair this TV Dave...They want you to buy a new one, instead!
back in the days Samsung provided a special tool to open those things to authorized service companies. I still have one somewhere
Your mannerisms are as sound as a pound super Dave!
I watched this on my $400 BENQ projector in the living room, which casts a 12’+ picture, yet weighs just a couple pounds and is approximately the size and weight of a PlayStation console. The disadvantages are: I had to crawl around in the attic to install another outlet and run long signal wires, so I have to own the house. But the advantage is a much smaller cheaper unit to service/replace. Also it has zero proprietary wire-up boxes or novel power arrangements. Mine has the 3D glasses capability, which means it can also do that screen-sharing trick the PlayStation can do. These monster flat screen tvs were a dream for decades now (famously: Elvis Presley’s multiple inset tvs in his living room). The reality, as with Presley, is a near-insurmountable service headache. I liked the BENQ so much I put in another one in the rumpus room downstairs!
There are ultra short throw projectors if you don't want to or can't mount it to the ceiling. They sit below the screen, less than a foot away from the wall. The downside is they require a special screen that will cost over $1000.
I didn't find any teardown of those projector did they use lasers with galvanometers or DMD chip
@@electronics-by-practice They use a DMD or LCD just like conventional projectors.
Just started watching this video, but I'll go ahead and put my wah-wah in now.
I’m amazed they don’t have standard connections on the back for future use as a tv and not an advertising screen. They could make money from selling it on.
11:50 have you tried that AOC CRT monitor?
Yes, works, another dumpster item I couldn't help but take.
AOC definitely needs a monitor....
@@AffordBindEquipmentwhat do you mean?
@@EEVblognice!
@@RWL2012 It was a joke about AOC (in the original comment), US congress woman.
1:18 in and already when you shine the light on the screen i see a crack on the top left center going down.
I have repaired this TV many times and the problem is that the current sense circuit for the Backlights is being triggered to power down. This is caused by any number of LEDs on the LED strips that are shorted out internally. This causes an overcurrent situation and the mainboard will flash the red power good indicator several times before sending the PSU back to standby mode. Its not worth it to replace individual LEDs that have gone bat but instead we replace the entire set of strips and Bob's y our uncle. Sometimes an LED will blow open, in which case you may not get any backlight or you will get partial backlight coverage from the still working LED strips. There is no point in trying another PSU, Mainboard, or TCON board until you strip the chassis down to the the bare insides to verify each LED strip. New LED strips are best to order from AliExpress using the part number written directly on the silkscreen of the LED strips themselves. A generic search for the correct parts using the TV's Model Number will only lead to confusion and likely obtaining the wrong set of LED strips. Best of luck. This one IS a fixer!
Hi. Congratulations on your first disassembled TV. The cover of which is attached with clips.::))
There was a massive 85 inch glass workbench stood right next to it.
It's turles all the way down.
@@EEVblog lol.
This takes "Right to Repair" to a whole new level! Typical big brand Industry giant tactics!
My heavy metal band name in 1982 was Dumpster Juice, I invented that name, I did! Now, there's an actual group called, Dumpster Juice!
One of the problems with these tvs is that if the buttons on the remote gets stuck down as in the power button the tv h cycle on and off as many times as the remote was pressed. It happed to my Samsung tv and it kept turning on and off like that. Even with the power disconnected it still remembers how many times the remote was pressed and no way to reset it. You have to let the tv cycle on and off until its done and it will work fine after that (it took many hours)
Oooh it connects like my odyssey ark.
Last week I learned my niece also has a samsung that connects to the same sort of box.
I got access to two of the things! 😅
Looks like you have an overcurrent situation through the LEDs caused by some of them shorting out. Had that on a 70" tv of mine. Put a few high wattage 8ohm resistors in series which gave me a few more years of viewing time although the picture was not equally bright in all areas.
Msrp on this tv was around $3800+ the image on this model is stunning.
yea that seems to be a screen short detect then it shutdowns after 2 or 3 tries just unplug the flat to the screen and power it on
That's some nice AOC CRT you've got there!
The cables part number might be BN39-02395A. It goes in between the two plastic things.
watching further into the video, maybe the PFC is done on the power supply within the TV and the 350v is just rectified mains.
My Samsung TV also died in a similar fashion. One day I was watching it and then suddenly it just went off by itself and would just flash the red light. Apparently you can fix it with some tape on the Flex cable forming from the panel but I never tried and just got it replaced under warranty
Man, are there courses in mechanical engineering teaching how to design annoying clips? The idea with the cable is great but it should have a screw to de-tension the cable to loosen all clips at once. We thoroughly need right to repair legislation.
Good were the days when things were held together by bolts and screws. These plastic clip affairs are always a gamble. Patience and frustration avoidance are the rules of the game.
Maybe there is a blown led in the backlight strips behind the screen. you may need to bypass the blown led .
This guy is like the guy you ask to get something fixed as a friend and je says hes busy meanwhile when its a fix for himself he does it instantly 😜✌️
if the panel has standard signals, you can connect it to one of those Chinese boards and power the lcd.
google the flash sequence for the make and model it will give you the error code
You have an unbroken panel. After watching the short, I still think it might be worth it to get a TV that has a broken panel that uses the same panel you have in here. Do a panel transplant. I own a 75" QLED TV and love the image quality. The TV with the broken panel shouldn't set you back more than a few dollars if you can pick it up locally.
Even for curiosity on the strange art the back panel is showing you when you light it up separately, I would try and get the panel in another TV.
Samsung LCD matrix some lines gets faulty and this talks to main board to shut down. You can put tape on ribbon cable tracks which can bypass protection .