Trashpicked Samsung LCD TV Repair?

hi everyone welcome back to Adrienne's digital basement what you see here on my coffee table is a trash picked samsung 1080p television 32 inch in size now I don't know why it was thrown away but it most likely doesn't work now funny is up here on my cart is I have an identical television which means I have the actual remote for the TV which might help in troubleshooting but let's not see if we can make this thing work and if there's a fault maybe I can fix it so let's dig in and take a closer look from a visual standpoint the monitor is a little bit dirty but otherwise seems to be in decent condition now I have the power cable connected and the red LED is lit here which is the normal behavior when this thing is off I don't think there's any cracks in the LCD although it can be really hard to tell in these dark ones there's definitely a few scuffs and scratches around the bezel otherwise it looks decent not much to report on the back of the monitor one funny thing is is this space right here is normally where the model number and serial number sticker goes it's been removed by someone this monitor doesn't really have a whole lot of inputs we have a single composite / component input here there's a 3.5 millimeter audio out an optical digital out antenna in which is for both ATSC which also does analog over here there's a regular power input over here on the side there's a USB port which i think is just for 5 volts out I don't remember if this thing even supports thumb drives and it has two single HDMI inputs in typical Samsung fashion there's a little bit of a joystick button thingy here that's for controlling when you don't have the remote control now this is the TV this is the other TV that I already had that has the sticker now since the sticker is completely missing off the other TV I have no idea if it's exactly the same model but it certainly appears to be alright I apologize for all the glare but we're up here in the living room which is where I had the remote control so I'll probably move down down to the bench to do a little more further testing so it's plugged into the power they red LEDs on let's hit the power button there's the normal Samsung startup beep which you can turn off luckily I have that turned off on the other TV I hate that sound and what happens is the power LED sort of blinks for a second might be hard to see all right the power ability LED is stopped blinking and we definitely don't see anything on the screen it did sound normal with the startup sound which would imply that the main controller is working so what I'm going to do is I'm going to take this flashlight here and I'm gonna shine it at the screen and see if the issue is just the backlight that's the problem and maybe we can see if we have an image or not all right well right off the bat I can see something on the screen let's get closer with the camera all right so you see there it says weak or no signal and it looks like it's just static you know as if it's an analog input so let me use the remote control to try to navigate around the menus a little bit but there's a good side means the back lights not working and I am pretty sure this is an LED backlight which means it's not likely to be burned out so possibly it's just a power supply problem all right I was able to navigate around the menu and I brought up the picture test and you see here it's showing color bars and it definitely looks like the whole image is displaying correctly I don't see any cracks or any kind of issues everything looks totally fine I was able to navigate to the backlight menu and it's not turned down not that you can turn the backlight to any kind of setting that would be off anyways but I'd say that issue purely stands with the backlight on this TV it has nothing to do with a software setting all right and I was able to plug in a little antenna to this and auto-tune a bunch of local channels so it's definitely working and I there's audio and it's picking up high-definition broadcasts of some commercial right now so I think the next thing is to take it downstairs pop the back cover off and let's take a look at what exactly we have going on cue whatever that is all right down on the bench I don't actually know how to take the back covers off LCD TVs I've never done it but I assume you to take all the screws out I just don't know if I need to take the base off so because of that I'm gonna use a towel here and I'm gonna lay the monitor down on the top of that facedown on the table and I'll take all these screws out then so it looks like under the base there's four more screws that hold the back on look you definitely need to take the base off yeah I think the joystick there's a little access panel here that we remove with a screw and I think it goes to the joystick there's a little cable in here black wire let's pop that off and there might actually be Clips as well ah there we go so we're in and it's pretty simple stuff in here over here is the main controller for the TV the joystick plugged into this port right here this which looks like a cable for a floppy drive on an old PC that definitely goes to these speaker modules here and here this controller does the LCD output which goes to this board I think this is called the t-con which is what controls the LCD directly and these two ribbon cables here are feeding the LCD panel that displays the image and as we saw when we looked at it with a flashlight we didn't see any issues with the image so I don't need to mess with that stuff over here this is the high voltage power supply converts 120 volts ac down to the voltages that the controller needs and over here this wire on the top is definitely the so while the backlight is plugged directly into the power supply and this right here is likely the back lights power supply that generates the voltages to drive the LED backlight there is a signal that comes from the main controller that enables the backlight basically turns it off and on and also controls how bright it is so there is possibly a fault on here that is not telling this to turn on the backlight but I think most likely the issue is either the power supply board or it's possible I guess the backlight has failed although looking at these wires there's two grays and two black wires and that makes me feel that there may be two separate backlight arrays in here like maybe there's a strip that goes half the width and another one that goes the other half so if one of those were to fail half the picture would be dark and not both I think I'm gonna plug this in and I'm gonna start with just physically wrapping on it seeing if that makes the backlight turn on so I went to turn on the TV and I figure out there was actually no way to do that because I was pointing the remote control at trying to turn on and nothing well this is the little joystick module that was in the back cover that I unplugged and if you notice right here there's the IR receiver so I got to plug this in before I can do anything all right plug this in here push the button the t-con board has three blue LEDs that's interesting so we definitely have no backlight on here and it's a bit hard a bit of a pain got to like lift this up to kind of look under here I can tell some water is actually dripped inside of the case there's some drip marks here I'm gonna use my plastic screwdriver here definitely nothing happening when I wrap on the power supply I think the next thing I'm gonna do is just check the voltages for this backlight wire here see if any power is even coming out of here at all I got to thank Samsung look at this they've labeled here what the pin out of the power connector is on the power supply but up here they have actually listed exactly what the voltages are in fact the LED driver output is at 91 volts at 450 milli amps the rest of these are available on their so for instance your ca says be 13 volts be 13 volts is 12.8 and 1.5 amps etc etc up here this is the back light LED control and you can see there D plus s - s + D - so guess those are the way it's hooked up even more interesting this power supply is a multi voltage power supply and I could have sworn on the back the back of the monitor where it shows the input just says 120 volts it doesn't say that it can actually work at multi voltage over here on the main controller board there's a connector here that says debug and I wonder if that's a serial line maybe it's worth connecting to I'm kind of jumping around but I was about to scope the output of the PWM signal and also the LED driver with the oscilloscope and I'm think it's gonna take the power supply off we're just gonna take a look at the back and see if we have CD broken solder joints these TVs are built down to a low cost at this point so they're extremely modular and very easy to assemble and disassemble so the through-hole components are gonna be the ones with issues so I'm just gonna focus on those specifically all right I've been poking around this power supply and something interesting this is the output connector for the LED driver you can see labeled D plus s minus s plus D minus well the reality is the middle three pins are all connected together you can see the thick traces here the one on the left here is labeled D Plus which is actually the positive driver voltage and this one here is the negative and the middle two are connected together so when you connect this led cable into here it seems to be connecting two strings of LED in series but I'm measuring 146 volts on the D plus pin here and looks like these power supplies the LED driver section definitely has an open voltage when there's nothing connected that's higher now when I measure D plus whether something's plugged in or not it's the same voltage 146 volts or around there abouts that leads me to believe there's something wrong with the LED drivers in here I think I'm gonna do is just disassemble this whole TV let's take the back cover off here to expose the LED drivers and see if we can see a fault maybe there's a bad connection there maybe they're just totally bad I don't know so now I've to try to figure out how to take this thing apart obviously the first thing I have to do is disconnect the ribbon cables from the t-con so you just lift up these little flaps and gently slide these out so those are disconnected and it looks like looks like there's just plastic clips to kind of hold this metal cover on so I'm just gonna pry these away little by little and like that and then I think this whole back cover comes off and that'll expose the LED modules and I have removed the tape because this cable probably feeds through this hole I'd assume this piece of tape there probably feeds back in there and then I can take this whole back cover off oh that was a little bit of a pain okay so what you see here is the actual LCD panel it's underneath this sort of light diffuser here it is these are the various layers and it all kind of shifted around so I gotta say the way these are assembled it's just all plastic so it all kind of moved around in there so I'm gonna have to try to kind of reassemble this if I'm even gonna try to get this TV back together again this is this is the backlight well it still has the electronics mounted to it but if I lift this up like this so there are the two LED arrays and they are definitely connected quite sure how they're connected together yes I see okay so they're in series but instead of them being connected internally to each other they each have two wires that go back to that connector and then that connector is wired in series on the power supply now I've read as one of the issues with these is all the LEDs are hooked up in series and if one of them blows out then the whole backlight fails and on some of the bigger TVs I suppose I think visually wired up individually so you might have sections of the screen that die but unfortunately with this particular TV it's small I think if one LED fails the whole thing goes open and we have no more backlight all right so this TV is connected everything is powered up right now I just have the LCD panel missing so we can see the back lights which are not currently running we have the multimeter and I'm gonna check for voltage so remember it goes in one pet one strip and it comes out these are all hooked up in series every single led here there's 12 per strip so it goes down one back then in the next one and then back to there so when I measure the voltage there are there are little pins here so there's a plus pin that's 153 volts and then there's the minus pin which should be the output 141 volts and that loops back the power supply comes back to this one probably into the spin on our 41 so that's the same as the - pin on there and then the - pin which should be the ground we're getting one volt this strip it seems to kind of go all the way down and back or getting voltage and then this one we're not seeing the output now there are these little blob things over the LEDs emitters kinda prevent us from measuring and checking each LED but the traces are available on here in fact there's a little test pad right there and there's a test pad right there so there's occasional test pads so maybe I can power up pieces of this with my bench power supply three LEDs I'm gonna unplug the power from the TV there it's gone and I'll probably unplug these connectors here so not sending any penny power back into the power supply all right so I have these two test leads connected to my bench power supply except for about nine volts 9.2 actually but only about 20 milliamps and there are no test points I've found on these strips but these are sharp test leads and I just sort of scratch away the solder mask and I have definitely found issues with this particular strip so here's an example if I connect here and let's see here one two three here so we light up those three LEDs no problems and I can you know with lesser volt I can get each one to light up and same thing if we go from right here so that's one two three we get three LEDs lit up no problem now I've marked a couple of these like this is a problem this one is a problem and there's one over here that's a problem this one I think is shorted is dead and it seems to have died and stayed connected in series if I try to connect it like this as nothing happens so at least the current passes through it so would light up the others but if I go here which should light up this one this one in this one we get nothing this one is dead and it's open now way over on this part of the board this one here is also dead so we go there and under the tape here I connect to the positively there we go so we get another one that's dead passes right through and the strange thing is if I do connect directly to it it flashes for a second and then it goes short and you know what that just killed it so it's totally dead now let's see if it's still no okay that died that died open so it was sort of passing but it was just flashing and then dying so that one's open this one is dead but passing current this one was dead and then going short i guess just like this one so I sort of blew those up the top strip all it's not well on this one either so these two LEDs are bad this one here when you turn when you give a power runs for a second then dies but it seems to pass current this one as well same exact problem so both of these died this one here is working fine and that one works good then this one here it's also flaky it's weird as sometimes it does work but most the time it just comes on in flashes and that one looks like a dead short according to the power supply this one not quite a dead short it's consuming 42 milliamps right now this one 42 milliamps yeah that's actually the current maximum I have allowed this ones drawing 42 min left out so they're all not working but everything else on this strip is fine all the other LEDs over here work just these three are bad and on this bottom strip this one is bad this one is bad notes here I have some of the little lenses popped off I took one off right here now the way I did is I just used this little pic here and just popped it off like that sort of comes off I assume these are kind of melted on or glued on who this led has a little black mark in the middle of it so you can see this led has a little black mark so that I think this one was one that was dead and open this one here and doesn't have as quite as much of a mark let's pop this one off this was another bad one got a little bad mark in there too up here these are the three on the top strip that flash and then pass current that one has no black mark that one has no black mark now and has no black mark so I took off the LED strips and yeah aluminum backed I mean it's gonna be kind of difficult to solder these are giant heat sinks essentially but six bad LEDs and I assume what was happening is they had failed and the TV was just driving these anyways and probably what eventually happened is the voltage goes up I think when some of the LEDs fail close meaning they're still passing current and eventually one of the other ones just gave up and failed open and that killed the whole backlight and then that's when the person threw way this TV so okay the question the question is at this point is should I fix this or shouldn't hi I gave a little quick test at trying to remove one of these LEDs and I didn't have any success I assume you need a lot of heat or maybe have to heat up this entire strip first that way doesn't it wick away all the heat and I looked online and it seems like replacement strips 20 bucks not so bad but I guess the question is is that there's this TV even worth fixing it did appear to work of course I took it apart it might have I don't I broke the panel in the removal process but anything is possible so at this point it's really a decision what should i do should i order the replacement parts for this or should I just part it out these parts are interchangeable with the TV I have upstairs so if I keep these components and toss the rest of the TV at the e-waste at least have spare parts for the TV upstairs if that ever breaks but yeah let me know in the comments section if you think I should go ahead and order these parts and try to fix this so I soldered on some cables on to the debug port here's my serial you are it's it's a 3.3 volts so of these three wires here the gray cables ground and then these are Rx and TX this one I connected but I don't need this is five volts that's not really used the reason why I didn't put a pin header on it's a different pin pitch than I have in stock so I just put wires directly into it unfortunately absolutely nothing happens interesting when you turn the TV on you just get this so that's it and if you change channels you kind of I'm pushing channel up/down and if I turn it off does that goes into standby interesting when it's off I you can push buttons and you get ends all right so that's it for this video sorry I didn't actually get the TV working I really had no idea what was wrong with it when I started so if you thought this was interesting in any way you know appreciate a thumbs up but you may not like this videos all because it's kind of different than I normally do so feel free to give her a thumbs down if that's the case put your comments and questions down below and don't forget to let me know if you think I should try to fix this thing or just scrap it after all all right I'll see you next time bye

Channel: Adrian Black

Views: 507,673

Rating: 4.7992735 out of 5

Keywords: Samsung, TV, Trashpicked, repair, DIY, LCD TV, UN32EH5000F, Samsung LED TV, Samsung LCD TV

Id: y_mz3dgSCnk

Length: 22min 2sec (1322 seconds)

Published: Sun May 05 2019