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: ua-cam.com/users/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 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.
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'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.
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.
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.
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'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?
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 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 ....
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 :(
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....
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.
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.
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
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.
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
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...
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) ...
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 .
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
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)
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.
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.
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 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?
@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) 👍👍👍👍👍🫡🫡🫡🫡🫡❤️❤️❤️❤️🫂🫂🫂🫂🫂🤝🤝🤝🤝🤝🇬🇧🇬🇧🇬🇧🇬🇧🇬🇧🇭🇲🇭🇲🇭🇲🇭🇲🇭🇲😊😊😊😊😊😊😊🎄🎄🎄🎄🎄⛄️⛄️⛄️⛄️⛄️
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.
Is that 230v * 1.41? Did they move the rectifier and capacitor to the external box and leave the other half of the power supply in the TV? If so that's actually kinda smart.
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.
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 bet only way that lt is intended to be repaired is throwing the whole thing away. So plastic tabs suit perfectly to manufacturers plans. And the oled panel will burn in couple years anyway if people occasionally leave it to show static image
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!
That connector looks beveled - I wish more connectors were engineered like that. USB C is reversible, but without the bevel I still can't get the things to plug in most of the time.
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.
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.
@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) 🫶🫶🫶🫶🫶🫶🫶❤️❤️❤️❤️❤️❌️❌️❌️❌️🫡🫡🫡🫡🫡😄😄😄😄😄
No, as the panel connectors on 75" tv won't match the board connectors on the 86" model. Of course they do that on purpose so parts can't be swapped between tv's ;-) Look at CRT tv's, all use a different flyback transformer even though the end result is picture on the tv screen. There was no need to have a different flyback in every single manufactered model of crt tv. Manufacturers are either really dumb or make everything incompatible on purpose to screw over the consumer.
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.
I would have thought it needs that other box to display or do anything. A wee sign of backlighting is about as much as you’d get I think. Worth keeping an eye out for a box on EBay etc.
There is at least some intelligence in the TV, as it has the usual control joystick. But I also suspect the guts of it might be in the box. Will cost me at least $500 to find out unfortunately.
I bet that TV has a problem with the LCD panel, try first disconnecting the flex cables and see if it no longer does the reboot loops. If so, try connecting only the one on the left and then the one on the right. If when connecting one of the flex cables the reboots return, that's where the problem lies. Then you can try covering with kapton tape, for example, 4 lines of the flex cable that are causing problems. Start on one side and cover the lines by peeling off the flex cable and covering the adjacent ones. Samsung panels are failing a lot (too much in my opinion).
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!
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! 😅
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.
What a strange design, is the separate box at least available with very long cables, for, like, public displays mounted far from the sources of signals? The back plate closed with plastic clips is so cheaply done...
Easy to hook stuff up as the TV is huge. The IO it always in the middle so how do you hook something up with out putting the TV flat on the floor or unhang it off from the wall and then flip it over on the other wall then turn it again to get to HDMI 4 ?
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.
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 think the issue might be that the capacitors on your 'dodgy power supply' aren't going to be providing a stable 350V DC, and the excessive ripple is causing problems with the lower voltage outputs or tripping the controller. The power supply is probably expecting an actually well regulated supply. I would try the 300V lab supply - it might be enough.
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: ua-cam.com/users/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 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.
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'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.
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.
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!!😂
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.
OMG I've opened these before. Watching you snap the back panel off, I'm screaming noo, pull the wire!
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)
It requires control signals from the one connect to power up properly. It perform like that to protect the panel.
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.
Knowing Samsung, it requires a handshake to fully turn on, which means it's worthless without the box.
Love the dumpster vids!!! Hope always!!!
Hey I undescribed 😊
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?
B350v is the PFC DC output from the PSU, its usually 380v in the UK, and VAMP is the power for the audio amplifiers.
One of my favorite segments next to mailbag.
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.
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
It's not going to do anything without the one connect box. Maybe see if its in the dumpster.
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 ....
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 :(
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....
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.
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. 😂
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
Siemens/Bosch uses the angled heat sinks on their induction panels/hobs
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....
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.
This reminds me of the phrase "there is no such thing as a free puppy."
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
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...
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) ...
Nice AOC minitor down there!
Another fine dumpster find.
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 .
Never go to the dumpster without camera and tripod !
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
I just replaced some caps on a 43 inch Samsung that was snapped together like that. What a PITA!
Nice to see Samsung calls for a 250V rated fuse for a 350V input ;)
watching further into the video, maybe the PFC is done on the power supply within the TV and the 350v is just rectified mains.
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)
There was a massive 85 inch glass workbench stood right next to it.
It's turles all the way down.
@@EEVblog lol.
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.
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.
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..
On many many Samsung tvs, the stand by light flashing twice like this means the screen has some sort of fault
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?
The cables part number might be BN39-02395A. It goes in between the two plastic things.
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It is not just the screws that are expensive. It is made not to be cheaply repairable.
Dave,this episode might be the start of a new channel: eevBOOM!
Cheers!
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.
That's one expensive Door sized tv you got there
Is that 230v * 1.41? Did they move the rectifier and capacitor to the external box and leave the other half of the power supply in the TV? If so that's actually kinda smart.
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.
Dave's favorite hobby! Dumpster Diving in rich man's neighborhood!
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.
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!
Maybe there is a blown led in the backlight strips behind the screen. you may need to bypass the blown led .
just use a LCD backlight tester to see if the backlight is ok and what voltage it sits at.
I bet only way that lt is intended to be repaired is throwing the whole thing away. So plastic tabs suit perfectly to manufacturers plans.
And the oled panel will burn in couple years anyway if people occasionally leave it to show static image
All modern tv's have an auto-off shut-off if the signal is missing. No one is going to show an image and just leave it there lol!
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!
looks like time to salvage what you can Dave.
I just saved one. Cost zero for the telly, £15 for the LEDs, half hour job. Bonzer
That connector looks beveled - I wish more connectors were engineered like that. USB C is reversible, but without the bevel I still can't get the things to plug in most of the time.
Hi. Congratulations on your first disassembled TV. The cover of which is attached with clips.::))
back in the days Samsung provided a special tool to open those things to authorized service companies. I still have one somewhere
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.
The red light blinking twice means its panel problem. either the panel is dead or there is an issue with the panel
if the panel has standard signals, you can connect it to one of those Chinese boards and power the lcd.
My Samsung TV did that too. Ended up that there were shorted LEDs.
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.
You are apparently, not supposed to repair this TV Dave...They want you to buy a new one, instead!
@EEVblog
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The language he uses is not how everyone talks here in au. That's just Dave ;-)
@g4z-kb7ct
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Your mannerisms are as sound as a pound super Dave!
Boring suggestion: won't this work as a screen replacement for the 86" TV? Just transfer the 86" guts to the 75" box?
No, as the panel connectors on 75" tv won't match the board connectors on the 86" model. Of course they do that on purpose so parts can't be swapped between tv's ;-)
Look at CRT tv's, all use a different flyback transformer even though the end result is picture on the tv screen. There was no need to have a different flyback in every single manufactered model of crt tv. Manufacturers are either really dumb or make everything incompatible on purpose to screw over the consumer.
That CRT monitor is worth a pretty penny if it works.
One of my backlights went out have half a screen on my 55in Samsung. Pretty lame only had it a year and a half
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.
Back lights are the most common issue. On some samsungs if you disconnect the main the back lights come on, the main is bad.
I would have thought it needs that other box to display or do anything. A wee sign of backlighting is about as much as you’d get I think.
Worth keeping an eye out for a box on EBay etc.
There is at least some intelligence in the TV, as it has the usual control joystick. But I also suspect the guts of it might be in the box. Will cost me at least $500 to find out unfortunately.
@@EEVblog Maybe you can borrow a box off some one else as well as the fibre optic cable to test it before you buy a new box ?
@@stormchaser300 return stuff doesn't work ? Just buy and return from a reputable store.
Clearly a TV that is designed to avoid being repaired. A trend that is becoming widespread for absolutely everything...
I saw a vid that says theres a tool (long pin) that you push in against the cable and that releases the clips..??...
Just started watching this video, but I'll go ahead and put my wah-wah in now.
I bet that TV has a problem with the LCD panel, try first disconnecting the flex cables and see if it no longer does the reboot loops. If so, try connecting only the one on the left and then the one on the right. If when connecting one of the flex cables the reboots return, that's where the problem lies. Then you can try covering with kapton tape, for example, 4 lines of the flex cable that are causing problems. Start on one side and cover the lines by peeling off the flex cable and covering the adjacent ones.
Samsung panels are failing a lot (too much in my opinion).
This takes "Right to Repair" to a whole new level! Typical big brand Industry giant tactics!
looks like fall off lenses (but I hear no rattling...) or dead LEDs
Maybe you can borrow or rent the box and cable somewhere?
Probably the only way. I'm not spending $500+
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!
The dungeon man!😂😂😂😂😂
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! 😅
Do you recon you could try n do a bit of trouble shooting to find out what wrong with it and see if it's actually worth repairing?
When you done the math what was it that you used
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.
What a strange design, is the separate box at least available with very long cables, for, like, public displays mounted far from the sources of signals?
The back plate closed with plastic clips is so cheaply done...
Easy to hook stuff up as the TV is huge. The IO it always in the middle so how do you hook something up with out putting the TV flat on the floor or unhang it off from the wall and then flip it over on the other wall then turn it again to get to HDMI 4 ?
They wont boot without the box, im my experience anyway. You must be able to borrow one from someone in your area ?.
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.
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 think the issue might be that the capacitors on your 'dodgy power supply' aren't going to be providing a stable 350V DC, and the excessive ripple is causing problems with the lower voltage outputs or tripping the controller. The power supply is probably expecting an actually well regulated supply. I would try the 300V lab supply - it might be enough.