LCD TV "tear down" and fixing (56k)

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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Thu Jan 19, 2012 1:48 pm

Yeah, I included asking the people that were doing the actual moving from the school building to the truck. :P

Sorry for the confusion, I am not referring to the brick ceramic power resistors, I will give you a picture soon enough. Hopefully within this hour! :P

Edit: Quick question, do you guys prefer pictures to be in the gallery thing I made (first post in this thread and in my other high voltage thread) or just embedding the pictures in my forum posts?

Edit2: http://archive.hak8or.com/projects/Syntax_Tv_Fix/index.html Pictures! I have to add in descriptions still.

Edit3: The actual embedded pictures!

Back of the unit to see the model number and other things if anyone is curious.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250749.JPG

The thick screws used to connect the stand to the tv.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250750.JPG

Close up of the screw that holds the stand together to the tv. They are rather thick and feel heavy, so those are some really nice screws!
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250751.JPG

Back of the unit with the cover off. Notice all the screw holes on the top most metal cover? If you wall mount this guy then that is where the weight of the entire tv goes. And let me tell you, it is A LOT of weight. I was barely able to lift it by my self, much less carry it.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250754.JPG

Now this is interesting. I don't know what this is meant to do as I never saw something like this before, but I suspect it is meant to sense how much light is in the back of the TV to adjust the screen brightness. I don't know why they wouldn't just put a photo resistor in the front, and I also don't know why there are three of them, with one angled and the other two right next to each other. Any ideas?
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250755.JPG

I call this "The Middle Board", because it is in the middle. Yes I know it is very creative. You can see the LVDS connection to the actual LCD panel on the left of the board. Black "tape" is covering it though. The 5 pin ic on the left part of the board is a switching ic, I have to check what voltage it generates, but I am guessing it is 3.3v since I see no 3v3 rails coming from the power supply, and I doubt they would use a linear regulator due to the large current demand of all the processing ic's, and I also doubt they would even consider putting a switcher on the logic board due to all the noise.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250756.JPG

Smushed power button. :( I had to take out the switch and temporarily replace it with a piece of wire till I get the power board working.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250757.JPG

Power board with metal cover.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250760.JPG

The power board, you should be able to tell right away that something is wrong here.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250761.JPG

Close up of the switching mosfets. I suspect they died when the power resistor blew.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250763.JPG

Close up of the blown resistor. Look at how far the "scorch" marks on the pcb go!
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250767.JPG

Back of the power board. They labeled the primary and secondary side at least. :P
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250768.JPG

I never saw headers used like this before to hold and provide extra safety to the mains rectification capacitor.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250770.JPG

Blown resistor from one side
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250771.JPG

Blown resistor from the other side. What a spectacular failure!
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250772.JPG

Power supply information
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250774.JPG
Last edited by hak8or on Mon Apr 06, 2015 9:54 pm, edited 3 times in total.
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Re: LCD TV "tear down" and fixing (56k)

Postby AndThen » Thu Jan 19, 2012 2:43 pm

Resistor is in this pic, and yeah thats close enough to ceramic, might of actualy lived if it was. You can see the wire bulges right up to the part it vaporised!
http://hak8or.com/pictures/Syntax_Tv_Fix/P1250761.JPG

What is part type is B1, not sure i've ran across this one.
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Thu Jan 19, 2012 3:39 pm

I embedded the pictures in this thread to satisfy both worlds. :P My logic behind the gallery thing is so that people can view the pictures in as much detail as possible without downloading 3 MB a picture, but I realize that I am posting a thread, and I don't want to post a thread with just a link to the gallery.

Anyways, I think B1 is a capacitor or some sort of oscillator, I see it some times on boards, but I don't know what their function is. My guess is a capacitor, since why else would an oscillator be there. Also, I did not notice the wire bulging, heh. I think the resistor was less than an ohm, but I can't really tell the colors.
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Re: LCD TV "tear down" and fixing (56k)

Postby Pisami » Fri Jan 20, 2012 1:04 am

What it looks like, it maybe is red gray silver gold green, and online calculator gives 0,28 or 0,29 ohm (5%), depending on is the gray gray or white :)
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Fri Jan 20, 2012 12:12 pm

Thanks for the color identification asdf. I tried to put in a resistor that is around 0.3 Ohms, and the fuse immediately blew. I did not want to push it so I just stuck in a 2.2 ohm (if I remember correctly) resistor. I have some more pictures I took yesterday, but I will be rather busy today, so I will probably put them up by tomorrow night. In short, the power supply I think is severely damaged and I don't really know what exactly failed, and most of the ic's on there are ones I cannot find online or just cannot buy. The mosfets are getting 120v spikes on all their legs including the gates, I think I spotted a few other failed resistors, and I am sure that 120v is too high for the mosfet drivers, which means they are gone too.

So, I have been working for the majority of yesterday to find the pin out of the power board, and I am pretty much done. I can't find the difference between the blue and yellow wires, but I know that both of them are a combination of turning the back light on and dimming control for the back light. I won't need to fiddle with that though since the power board does nothing with those 2 signals, since the traces literally go on the side of the pcb from the logic board to the CCFL driver boards. I have a very good idea on what the rest of the wires are on which voltage rail is which. So, I want to design my own power supply for this, and it will surely be very challenging! 24v at around 8 amps is quite hefty, but at least I have a good idea of the specs thanks to other boards online from this company that seem to be extremely similar. I am getting excited already. :P
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Re: LCD TV "tear down" and fixing (56k)

Postby Pisami » Fri Jan 20, 2012 12:24 pm

Just a random thought: Could you use camera to detect colors, like CHDK firmware in Canons? I'm not sure, but it could be possible to extract RGB values in the image, maybe you would need white (or just known) background...

I REALLY don't know (it it's possible), but that feature could be useful.

Hopefully you get the power supply to work!
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sat Jan 21, 2012 2:12 am

I could have sworn I posted in this thread in response to you asdf, but it seems to have disappeared! :(

I remember saying that my point and shoot unfortunately does not support anything like CHDK (curses you panasonic!), but I like your idea, though I eventually realized something. When you take a picture with my point and shoot, a gray might turn into a silver, and vice versa, due to the lightning. The white balance on my camera is also a bit wonky some times, so I cannot be sure that the colors in the pictures are the real colors. But, my next purchase of a point and shoot will definitely be, if not only, for chdk. I really want direct control over shutter speed, iso, aperture, get RAW, run nice scripts, and further mess with it. I have how my timer is only 2 seconds or 10 seconds, and how I can't control the shutter speed. I mean, camon, it can go to 60 seconds in Starry sky mode yet it still takes 120 seconds to take the picture? Pah! >:(

Anyways, thanks. :) I got to work with the gallery a bit more, and I made the description window movable! I used jquery ui for that, but for some reason resize was not working correctly so for now it is only movable. I also put this "feature" only on the syntax gallery for now to test it out. (Just realized the width of the descriptions has been reset, woops, I will fix that soon) Can you guys check that out and tell me your experience with it, like does it work, is it useful, a pain in the butt, super awesome, things like that.

Edit: An awesome app note from microchip regarding smps's http://ww1.microchip.com/downloads/en/AppNotes/01114A.pdf

I also put a temporary page in "projects" on my site that links to these galleries so google can crawl my site better. I took a lot more pictures but I still have to upload the rest of them and the forum re sized pictures.

The pictures are worth the wait, I promise. :P
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sat Jan 21, 2012 4:58 pm

Woops, I accidentally uploaded the html file. You guys can see the gallery with around half the pictures I meant to upload! I decided to start linking to the chips' datasheets and other relevant information, hopefully it is a good addition. Also, the descriptions I will try to make more detailed and add in useful information here and there. Any feedback would be welcome! :)

I will add in the pictures to this forum once I finish with describing the pictures.
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sat Jan 21, 2012 7:33 pm

Oh gosh, I spent nearly all day working on adding in these pictures! D:

I more than doubled the amount of pictures I had, and the descriptions are very descriptive this time, and I linked to the datasheets of important ic's. For now I will just link to my site, and later I will add in the pictures to this thread with the descriptions.

http://archive.hak8or.com/projects/Synt ... index.html

edit: And here they are! :)
This is in general how my entire setup looks like while working on the tv.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250779.JPG

A close up on the problem area. From right to left: Power board, middle board, logic board.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250781.JPG

Did you know that the entire logic board can be taken out by just unplugging that one big purple connector from the middle board?! I have never seen something like this before, that is just flat out amazing!
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250782.JPG

Logic board compartment that I took out in the previous picture. Rather large and it looks very bland and simple.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250784.JPG

Other side of the logic board compartment. Nothing spectacular here, normal HDMI and video and whatnot.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250785.JPG

Getting around to opening the compartment, but the two cords (black and silver) on the right are holding it closed.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250786.JPG

Oh cool, three boards!
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http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250788.JPG

Unplugged the cables so you can get a better view on the boards inside. On the left most board I see a heat sink with quite a bit of decoupling capacitors, some RAM or Flash chips, and lots of little chips, and the HDMI connections go to this board, so I am presuming this has the main processor on it for this tv. On the right bottom board you can see a TV tuner with the footprint for a 2nd optional tv tuner. It seems like most of the analog signals just go through the board. On the top right there is a board that is connected to the "analog" (bottom right) board, and I do not know its function just yet.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250789.JPG

First off, the left most board. Looking closer and you can spot two major chips, which is the heat sinked one and another chip on the bottom left. On the left of the heatsinked chip there are two ram chips (Most ram chips have very similar chip packges) and ontop of the heatsinked chip you can spot another chip with a sticker!
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250791.JPG

The numbers and serial for the board we are looking at right now.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250794.JPG

The chip with a sticker surely is a flash chip! Flash chips are used to store the firmware for things such as TVs, game consoles, and phones, anything pretty much that has some sort of complex digital functionality. The sticker is there to say what it has been flashed with so the people assembling these guys know what tv the board is meant to be paired with. A 42 inch tv that uses <a ATSC href="http://en.wikipedia.org/wiki/ATSC_standards, and L2.3 I presume means the revision of code. The marker "20" mark, I have no idea. Maybe batch number?
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http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250793.JPG

Here is the chip with the sticker taken off, yummy! It is a MX29LV160BBTC-7016 http://archive.hak8or.com/projects/Synt ... BTC-70.pdf 16Megabit Flash memory ic, as I thought earlier. It is possible to get the data off this flash chip without much trouble (very easy to interface) and then knowing the processor the data is meant to you can run a disassembler on the code to find the assembly language. It is a complicated process, known as reverse engineering, and often you have to write the disassembler yourself, unless of course you just use IDA http://www.hex-rays.com/products/ida/index.shtml and hope someone had already written the disassembly plugin/script for your particular processer. Also on these chips you can usually find the pictures and audio used in the TV, and if you are REALLY good you can add in functionality, emphasis on really good. Ofcourse, there is always the possability that the flash is encrypted, which is a whole other ball game. In short, this is the flash chip, and if you are super mega awesome you can make this tv do anything you could want.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250797.JPG

The ram chips used in this guy.M13S128168A-6T http://archive.hak8or.com/projects/Synt ... BTC-70.pdf 128 Megabit, 166 MHz This tv uses HDMI, which is increadibly bandwith intensive. Here is some math to show just how much bandwith HDMI may contain.
-------------------------------------------
720p is 1280 x 720
Assuming each color is 8 bits (255 values for Red, Green, and Blue)
Not including all the other signals like Vertical and Horizantal sync
Would give you: 471,859,200 Bits per frame or 471.9 Megabits Per Frame
Assuming 30 frames per second: 14.16 Gigabits Per Second
-------------------------------------------
That is just video by the way, HDMI also handles audio and new cables also do ethernet. I assume this TV is HDMI DRM compliant, which means that it would have to be able to decrypt 14 gigabits of data per second, and you have to store that data somewhere, hence the Ram ics. HDMI is capable of much faster speeds, so feel free to check HDMI on wiki. Also, those chips have to store uncompressed pictures and audio, not to mention the OS that the TV is running on (rarely linux, most often a proprietary OS). So, HDMI is very bandwith intensive, most if not all flat panels have RAM chips, and there is a good reason why that processor has a heatsink.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250796.JPG

The HDMI connectors fo to this guy, but of course this is a "secret" ic so you cannot find the datasheet for it unless the Silicone Image gives it to you. I presume this chip has the no longer secret HDCP keys in it, hence not being able to find the documentation anywhere.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250799.JPG

This is the TV tuner card, nothing really special in there. The footprint under the top LG Tv tuner is for another tuner, presumbly with two antenna jacks. When companies make things like LCDs or tablets, the PCB is designed to accomodate all possible models, since it would cost a lot more to make seperate versions of PCBs. Like, in tablets, there are 16GB models, 32GB models, and 64GB models with a 3G connection. Chances are that the PCB will be exactly the same in all the models, the only differences are that the Flash chips on the PCB are higher density and the 3G modem is populated. That is why you can often spot some really large things "missing" on the board, like unpopulated foot prints. So, the TV tuner there is lacking probably because this is a lower end model.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250792.JPG

Numbers and serial for the TV tuner card. U3 (big shiny pad and legs) is the footprint for a votlage regulator I think. You can tell by the decoupling capacitor cloes by and all the filtering inductors close by. I think it is missing because the 2nd TV tuner was not populated, so it did not need the extra voltage rail, hence the missing votltage regulator. Or maybe since the 2nd TV tuner is missing the existing tuner can use a less hefty power rail which was originally meant for something else.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250798.JPG

I wont take pictures of the undersides of the boards that you saw earlier because it would be too much of a hassle (there are nuts holding them in place to the back), so instead here is a look see on the third board (top right)! This is a hefty board it seems. You can tell there is a BGA chip on the other side because of the tiny holes on the middle of the board, not to mention the tiny decoupling capacitors on the footprint. You can also see "squiggly" traces leading to the BGA ic, and those traces are squigly for impedance matching which means that each high speed trace has the same length. At very high speeds (50+ MHz) traces need to be the same length because, believe it or not, electricty does take time to "travel", and the rise/fall times also need to be controlled. Some good app notes for information about high speed PCB design can be found http://archive.hak8or.com/projects/Synt ... /an246.pdf and http://archive.hak8or.com/projects/Synt ... _Speed.pdf .The abundance of high speed traces and what seems to be a pattern leads me to believe that there are some RAM or Flash chips on the other side of the board. Also, notice the series of dots resembling a 2X7 header footprint on the left of the board, could that by any chance be a non populated JTAG connector?
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250800.JPG

Close up of the header I mentioned earlier.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250802.JPG

Model and serial for the board in question.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250801.JPG

Trying to take the circuit board off to see what is on the other side, and look at what is holding it down! A heatsink, so I am guessing that is in fact a BGA chip (complicated chips usually are BGA, especially things like SOCs and processors), but look at the design. A heatsink gets hot, and it has the fins to help radiate the heat, and if it is passively cooled, airflow is very important. So, why is the top of the heatsink stuck on with a heat conductive pad like that to the metal case? What were they thinking, is it even worth the money to stick a pad like that there? There is barely any contact between the heatsink and the conductive pad. From my understanding, this is a horrible design decision and a waste of the ten cents that pad cost.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250804.JPG

Top side of the board. Oh now this is interesting, we got our selves four ram chips (as predicted earlier), one flash chip with a sticker, another stick with 520MB on it, and another tuner. There is also a push button on there! It does also look like that header is JTAG, as the traces are going to the BGA chip. Often times in complicated boards with a processor of sorts, there is a JTAG used to program the bootloader and debugging. A bootloader is the first peice of code (programmed to the actual chip using JTAG) a processor runs; it setups up configuration bits for the processor like what oscillator to use and the caching scheme, tells the processor where the rest of the code is, and then gives up control to the next step in booting, like a L2 bootloader or straight to the OS. If there is security in the unit like an encrypted Operating System, then the boot loader contains the keys to decrypt the OS and check if the OS is "signed" using those keys. If you can get JTAG access to a processor, you have full control over everything that peice of silicon does.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250807.JPG

The labels for the board and tuner. Notice the unpopulated connector on the left bottom of the board.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250808.JPG

I see marks from LG and Phillips everywhere, regardless of the brand of the Tv. TV tuners are usually enclosed in metal containers like this for very good reason. Tv signals reach you at very high frequencies (54 MHz - 890 MHz), and to work with those signals you need a very controlled enviorment, so that metal case acts as RF shielding.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250809.JPG

The suspected Flash chip with the sticker seen earlier with the button and header. Also, I just spotted the 4 prong header on the left of the chip next to the capacitors. I am increadibly curious what the button and the header are meant to do, and I would press the button if it were not for the risk that the button is something that could possibly clear the flash or something. Also, why would they put a button there, where no one can reach it except when fully dissassembled. I am thinking it has something to do when programming or testing the boards, but why not just use the JTAG for that instead? Seems like a waste of money to put that button there. Anyways, the sticket indicates that this is indeed a flash because there is a filename (20050726.bin). Bin files are binary files which are normally programmed onto flash chips. The filename obviously shows the date the file was compiled, which is about seven years ago.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250810.JPG

And there goes the sticker! This Flash chip http://archive.hak8or.com/projects/Synt ... BTC-90.pdf MX29LV320ABTC-90G very similar to the earlier flash chip (MX29LV160BBTC-70) except for a few things; this chip is larger (32Mbit vs 16Mbit) and slower(90ns vs 70ns). Why they designed the LCD to have two totally seperate processors like this I have no clue. A short googling gives me nothing for that file name sadly. :(
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250812.JPG

And these HY5DU281622ET-5 http://archive.hak8or.com/projects/Synt ... 2ET(Rev1.0).pdf are the Ram chips on the board. There are four of them, each being 128 Megabits, which gives a total of 512 Megabits or 64 Megabytes. Same as said for the earlier ram chips on the other board, these guys are used by the OS and whatnot for the Tv. Question is, why is there so much more ram on this board, it seems to interface only with the Tv Tuner, and the cable does not indicate that there are any high speed traces between this board and the other board with a processor. I am dumbfounded as to how the system design looks in this tv.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250809.JPG

The four pronged header from earlier seems to be connected to the processor on this board, maybe it is for "upgrades" or repogramming for the customer? Or it is a connector for an optional fan?
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250817.JPG

After putting back the logic compartment thing from earlier, we go back to the boards we originally saw in the begining of the tear down. This is the middle board that the logic compartment was plugged into. The connector on the left is for the menu buttons on the bottom of the tv, I forgot what the red and white three pronged connectors were for, the two rectangular connectors next to those are power connectors, and the connector on the right of the board is for LVDS to the actual LCD panel. You can see a switcher http://archive.hak8or.com/projects/Synt ... 30.pdf.pdf GM7130 on the board, I presume it is for the 3.3 volt rail, as there is no 3.3 volt rail from the power supply. Also, there is no marking on the chip to tell what voltage it is or if it even is adjustable. The chip on the left has no markings so unfortunately I cannot say much about it other than it has a heatsink on it. The connector next to the LVDS is to the photodiode board shown earlier, and I have yet to find what that board is meant to do.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250820.JPG
Last edited by hak8or on Mon Apr 06, 2015 9:55 pm, edited 4 times in total.
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sat Jan 21, 2012 10:27 pm

Underside of the board. The blemish you see on the board is due to the switching regulator and all the heat it generates. That should not really happen, they should have put a small heatsink on the switcher to prevent the heat from damaging the PCB, but I guess the additional cost was not worth it.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250821.JPG

This is the CCFL driver board for the backlights. There are two of them, one on each side of the TV, and they are connected to each other with that white FPC. The boards get 24volts (red cables), ground (black cables), and yellow/blue for dimming and turning the backlights on and off.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250822.JPG

This is the best picture I can get of the FPC area. I presume that the square IC on the left is what keeps the backlights synchronized with each other. I sadly was unable to find anything for that IC, but I found a datasheet for the rectangle ics! They appear to be confidential. http://archive.hak8or.com/projects/Syntax_Tv_Fix/datasheets/gm7130.pdf
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250831.JPG

Me trying to be artistic and get a good new wallpaper. :P
Image
Image
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250844.JPG
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250845.JPG
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250848.JPG

One thing I realized when I powered it up without the cover on the logic compartmnet. Leds light up! That is fantastic! It means that part of the logic is still working. The power supply constantly generates 5v (+5vS B) even when turned off so it can turn back on when sensing you pressed power on the remote or the power button. It seems that +5vSb survived in the power board, even though all the other voltage rails died. :P
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250851.JPG

This is the power connector on the power board. As I am scraping the power board due to it seeming to be damaged extensively like a destroyed switching regulator, blown mosfets, and 160 volts in all the wrong places, I need to find the pinout of the board board. My conclusions are this, from left to right: blue and yellow are a combination of backlight on/off and dimming, black is ground, and red is 24v.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250857.JPG

And the pinout of the other two connectors, from left to right: first wire is +5vSB, next wire is PS_on, white is +5V, black is ground, blue and yellow is a combination of dimming and enabling the backlights,red wires are 24v, and black are ground.
Image
http://archive.hak8or.com/pictures/Syntax_Tv_Fix/P1250858.JPG

I had to continue it because my post was too big.
"Your message contains 20351 characters. The maximum number of allowed characters is 20000."
Last edited by hak8or on Mon Apr 06, 2015 9:56 pm, edited 2 times in total.
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Re: LCD TV "tear down" and fixing (56k)

Postby ian » Sun Jan 22, 2012 4:11 am

Nice pics.

not to mention the OS that the TV is running on (rarely linux, most often a proprietary OS).


Did you pull the heat sink off the processor? I'm sorry if I missed it. Do you think it really runs an OS? My guess would be something totally coded from the ground up, the way most PIC/AVR/ARM stuff is.
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Re: LCD TV "tear down" and fixing (56k)

Postby Pisami » Sun Jan 22, 2012 9:27 am

Very nice pics there! As far as I know, my LG TV runs Linux, so it is possible. I have some pictures of disassembled electronics, too. Do you want them here somewhere, should there be a thread or something for "inside electronics"?
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sun Jan 22, 2012 12:36 pm

ian wrote:Nice pics.

not to mention the OS that the TV is running on (rarely linux, most often a proprietary OS).


Did you pull the heat sink off the processor? I'm sorry if I missed it. Do you think it really runs an OS? My guess would be something totally coded from the ground up, the way most PIC/AVR/ARM stuff is.


Well, I know that things like LG TV's use full blown Linux, a lot of set top boxes use Linux, and a few other electronics use it too. Or maybe not an OS like windows or Linux, but a proprietary RTOS coded in house. If not an RTOS than at least a state machine of sorts, though an RTOS would make more sense in this case. It has to keep checking for remote information, put a overlay on the screen, some tv's have Ethernet connections, all while displaying the main video.

Here are some links to different brands using RTOS's of sorts. Nucleus is one of the top closed source OS's out there I think.
http://www.iqmagazineonline.com/magazin ... -AQUOS.pdf
http://blogs.unbolt.net/index.php/brinl ... runs_linux
http://wiki.samygo.tv/index.php5/Main_Page

Also, my logic is that if a company like samsung puts linux on its tv's and doing so not for a PR stunt, then there is good reason it is running an OS like that on the tv.

And, sadly I did not take the heatsinks off the chips. I don't have any AS5 to replace the dry thermal paste after disturbing it when lifting it off the chip. :( I have heard though that toothpaste is a not awful replacement though, so I might check in on that. :P
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Sun Jan 22, 2012 12:38 pm

asdf wrote:Very nice pics there! As far as I know, my LG TV runs Linux, so it is possible. I have some pictures of disassembled electronics, too. Do you want them here somewhere, should there be a thread or something for "inside electronics"?


I envy you and your linux Tv!
If the electronics are TV stuff, I guess you can put them in this thread. :P The more the better! :)

I also put in the link to the "confidential" pdf.
http://archive.hak8or.com/projects/Synt ... gm7130.pdf
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Re: LCD TV "tear down" and fixing (56k)

Postby hak8or » Tue Jan 31, 2012 11:17 am

Yes Yes, I know, there has not been much activity lately. I am currently working on a database thing on my site so I can keep track of all my components and the quantity of them that I have. I never played with SQL or PHP, so this is all very very new for me. Anyways, for the TV, I cannot find a cheap power supply delivering 24 volts at 8 amps and 18 volts at four amps, so I will try to make a SMPS myself. Instead of going with a transformer I will try to go with a buck converter, as this is my first SMPS design and buck seems to have less complications than a transformer based supply. To do this, I obviously need new parts, so I decided to stick with digikey and try out their free shipping if paid by check. I emailed for more information and here is what I got, so I can spread the word.

http://dkc1.digikey.com/us/en/mkt/Terms.html
When a check or money order accompanies your order, Digi-Key pays all shipping and insurance (our choice for method of shipping) to all addresses in the U.S. and Canada.


Digi-Key does accept personal checks from customers within the U.S. There are two ways you could pay using a personal check. First, you could do what we call a pre-paid order, where you would send us a list of your parts. (either mail or you could enter the items on the website and then under billing select contact me, and then in order notes reference that you will be sending in a check.) Once we receive the copy of your parts we would let you know the total and once we receive your check in the mail we would then process the order and ship. No stock is reserved until we receive the payment. Digi-Key would pay for shipping which is usually shipped UPS Ground. Once the order clears the shipping department if you provide an email address you would receive an automatic email confirmation stating the order is being shipped. Second option would be to place an order via phone, fax, email, or on the website and select to pay via COD. With this you would pay the UPS or USPS carrier when they deliver your package. You would be responsible for shipping charges and I believe there would be a COD charge as well. If you use a personal check for that we would just need the bank information from your check. (Bank name and location, check #, routing #, and account #...ect)
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