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    Westinghouse LD3255VX Main Board eBay replacement.

    I need some advice on a main board replacement for a Westinghouse LD3255VX 32" LED tv set. It was totally dead when I got it. No signs of life whatsoever. After googling it, and no luck on the problem even close with the exception of bad caps forum, I feel that this might be the best place to ask this question.
    I bought a replacement board for this TV off of eBay, and did not even notice until I hit the "buy it now" button that there are 3 different boards for this model of TV. duh~
    Anyhow the listing states that I may have purchased the wrong board for this TV since there are multiple versions. It does however list my version number(TW61301-K032A) as a fit for this board in the listing. The board I removed is a 60EB3UM12A and the board I bought is a 60EB3UM12C. Like an idiot I did not even think that there was likely several versions of this main board, and am wondering if I need to return this while I can (30 days) and order the 12A board.

    https://www.ebay.com/itm/163319254450

    Oh, BTW, the original board is a dead short with the PS plugged in, and looks totally cooked from the burn marks on the back. Voltage at the PS jack goes to zero volts with the PS 19V DC 4.7A plugged into the board. This is defintely a throw away type board. I have trouble even reading the chip markings, much less soldering on new components.





    Attached Files
    Last edited by electicman; 02-15-2019, 12:07 PM.

    #2
    Re: Westinghouse LD3255VX Main Board eBay replacement.

    https://www.shopjimmy.com/westinghou...main-board.htm
    Please read the caution about the board, or contact SJ and ask questions.
    Last edited by budm; 02-15-2019, 02:20 PM.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: Westinghouse LD3255VX Main Board eBay replacement.

      Originally posted by budm View Post
      https://www.shopjimmy.com/westinghou...main-board.htm
      Please read the caution about the board, or contact SJ and ask questions.
      Thanks for the reply, Bud. I had already seen the cautions on SJ with all of the google searching I have been doing on this board.

      All of the connectors and ribbon cables seem to plug in properly. The front red indicator comes on as it should with the new board, but no back light LED's or visible picture. I can't seem to find a pic using a flashlight either, but it has marginal batteries, so am unsure there.

      I haven't probed it very much, but at first checks, I am getting 19.2 VDC PS voltages at both sides of D21 and D22.
      I completely disassembled the panel today and used a 5 VDC power supply and some needle probes to test every one of the 80 LED's that run across the bottom of the display panel.. inside the display. All 80 LED's work. I would assume if anything were shorted, it would also not allow the corresponding LED to light when power is applied directly to the LED.



      Attached Files
      Last edited by electicman; 02-15-2019, 04:24 PM. Reason: Typo's

      Comment


        #4
        Re: Westinghouse LD3255VX Main Board eBay replacement.

        Yep, call shopjimmy or electroparts etc. and ask m if c will compat with a.

        Comment


          #5
          Re: Westinghouse LD3255VX Main Board eBay replacement.

          That LCD panel uses Edge lit LED assemblies, sometime those fragile ribbon cables which go into the panel to the LED assemblies have insulation nicked so it is shorted to the chassis. You should check the resistance of each pin of the cable to see if any of it is shorted to chassis.
          Last edited by budm; 02-15-2019, 04:50 PM.
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

          Comment


            #6
            Re: Westinghouse LD3255VX Main Board eBay replacement.

            I battled the same board with the help of this forum. See: https://www.badcaps.net/forum/showthread.php?t=66475

            Check the MC34844A chip output, but be careful or you may ruin it like I did. Measure off the corresponding nearby component, not the chip itself to avoid shorting the chip. Lesson I figured out via the stupid method. If this chip is bad, it is a tough one to replace. Part is cheap, but removal and install for me was not easy.

            When I tried to source a board I could not find one for my revision. After looking at pictures of all similar boards I figured the only difference was the EEPROM, which I bought at SJ. I suppose you can just pull the one off your board and move it over.

            As for the brown spots - my board had the same. I don't think it is an issue.

            The journey I had, if you read my post, was brutal as I had to adapt another board as I didn't want to spend the money for the correct board. Dumb, yes, but it was a cold winter. An $80 board on a $40 TV made no sense, those were the prices at the time. I ended up buying a single channel board and moving components over to make a second channel. Idiotic, but it was cold out.

            Per budm's #5 post, check the cables as they enter the panel. I just dealt with a short here on an EW32S5UW (pretty similar TV, but w one LED strip vs 2). I used static tape and then electrical tape cut to fit down into the slot. I then added three layers of some thicker tape to build up the height so where the cable goes 90 degrees it is supported by the ticker tape and can flex towards the aluminum frame. After this I secured the cable down. On the EW32S5UW the cable when compressed would short on the aluminum panel as the cable does not seat all the way into the slot - the exposed traces when the plastic housing/bezel/case is installed pushes the cable which then touches the frame. That is my theory as my fix is working.

            Comment


              #7
              Re: Westinghouse LD3255VX Main Board eBay replacement.

              Thanks to everyone for the replies. I did try several times to call Electro parts to ask if the A and C boards will interchange, but not once had anyone answer, nor return my calls. Of course in this day and age of scam after scam phone calls, and google voice telemarketers, if no message is left, any call returned may be shrugged off as another identity theft scammer. 6 freakin calls TODAY! <sigh>
              From my understanding from reading the thread that Kg74 has on the same TV, it's my understanding that the eprom software is the only difference between boards, so I ass-u-me that the TV should boot and run, except it might have a few gltches from the wrong software. at least the back-light? Is this thinking correct?
              I did notice the other day that half of the back-light LED's flicker briefly on one side and the cathode (dimpled edge) voltage on D21 hits~56 volts for a few seconds, drops to 19.1 volts, then dies. It seems the same problems listed in this thread also apply to this TV. I have read through it a few times , but just recently started to troubleshoot this TV. The SMT stuff can be pretty intimidating, since I can hardly read the numbers, but I do have a magnifying lamp and a weller heat gun. :-)

              When I first started looking at this dead set, I ran across all of the info on the ribon cables being shorted, but was unable to locate any shorts to chassis, and also pulled up the glued down ribbon cables and added in a small piece of electrical tape to the sharp edge to prevent them from shorting. No shorts were noted with my harbor freight elcheapo meter. I also have a set of sharp probes that I have had since I was a flight simulator tech made out of thin piano wire stuck into a ~.5" wooden dowel, then sharpened that I could slide into most any aircraft plug to check circuitry that work great on this tiny smt stuff.

              https://www.badcaps.net/forum/showthread.php?t=66475

              Can you tell me if it was just the 34844 chips, or were other components also smoked?

              At this point, I may order a few 34844 chips and perhaps a eprom to match the "A" board to try and get this dead set working and off of my kitchen table.

              it may not be as cold in STL than northern MN it's stiil cold here. I feel your pain brother. lol
              Last edited by electicman; 02-28-2019, 04:59 PM.

              Comment


                #8
                Re: Westinghouse LD3255VX Main Board eBay replacement.

                To be clear, I visually inspected the various board pictures I found on the internet, and I could not see any changes. I looked very close, matched main chip numbers ... There could be changes I did not see, but reading similar posts where others used different boards I came away with the "concept" if the panel is the same it should work with the correct EEPROM. The EEPROM has the relevant software.

                Have you tried running your "C" board to see what happens? Again if the panel is the same it should work without issue - no need to change the EEPROM.

                To answer your question and refresh my memory I pulled out my old board (an "A"), and a spare board for a smaller 26" set of the same basic design (a "D"). The 26" board is the one I transplanted parts from my 32" fried board to, and removed and added a few items so it would match up (plus EEPROM). Looking at what I removed and replaced the differences in the boards was the 26" is a single channel and the 32" dual channels (two 34844 circuits).

                I would look at my original post, and go through the testing steps the board members helped me through. Make sure you are getting the correct readings to and out the various pins on the 34844. You may need to pull up the data sheet for it - it has plenty of information on what you are looking for and what tests you should be making. Again, don't take readings off the legs of the chip, but off the nearest component - following the trace. On mine only one chip was bad at the start. After a slip I blew out the working 34844.

                It would not surprise me that on your bad "A" board the original owner had one side fail and kept using the TV. It works fine in this capacity, just dark. After more use in this manner the second side is now almost gone. Do the testing of what is going in and what is coming out of the chip and you will know if it is only the chip.

                If you think you can change out the 34844 chips I would start by replacing those two only. They are not expensive. I would do one channel at a time and test out the good side to see if anything else could be bad.

                To work on the chip I first tried hot air, but it tore up the pads and blew some smds around. In the end I put a fat tip soldering iron on the bottom of the board, and blew hot air from above and the chip was easy to remove. I fashioned a copper heat shield to protect the surrounding areas. I had my original board to learn from - which in the end I completely destroyed. So I am trying to save you from the same mistakes.

                Clean up the area well, and use solder paste for the new install.

                Comment


                  #9
                  Re: Westinghouse LD3255VX Main Board eBay replacement.

                  Three additional items, the 34844 chips are located at U4 and U6. I wouldn't order an EEPROM chip as your problem is most likely, your testing will determine, the 34844 chips.

                  Before ordering anything, after you do your testing, I would try to remove the 34844 chips. You may destroy the board -if you are skilled and they come off clean - order away.

                  Comment


                    #10
                    Re: Westinghouse LD3255VX Main Board eBay replacement.

                    Originally posted by Kg74 View Post
                    Have you tried running your "C" board to see what happens? Again if the panel is the same it should work without issue - no need to change the EEPROM.

                    You may need to pull up the data sheet for it - it has plenty of information on what you are looking for and what tests you should be making. Again, don't take readings off the legs of the chip, but off the nearest component - following the trace. On mine only one chip was bad at the start. After a slip I blew out the working 34844.

                    It would not surprise me that on your bad "A" board the original owner had one side fail and kept using the TV. It works fine in this capacity, just dark. After more use in this manner the second side is now almost gone. Do the testing of what is going in and what is coming out of the chip and you will know if it is only the chip.

                    If you think you can change out the 34844 chips I would start by replacing those two only. They are not expensive. I would do one channel at a time and test out the good side to see if anything else could be bad.

                    To work on the chip I first tried hot air, but it tore up the pads and blew some smds around. In the end I put a fat tip soldering iron on the bottom of the board, and blew hot air from above and the chip was easy to remove. I fashioned a copper heat shield to protect the surrounding areas. I had my original board to learn from - which in the end I completely destroyed. So I am trying to save you from the same mistakes.

                    Clean up the area well, and use solder paste for the new install.
                    The C board is the only one showing ANY signs of life. The old board is a dead short to the PS, and the 19.2 VDC drops to millivolts when I plug in the old board. My original post was made after I had already installed the C board, but had no back-light.
                    I did notice the other day that the back-light is working on the left side of the display briefly (flickers for a few seconds, then dies and the voltage on D21 cathode slowly drops to 19-24 VDC) It appears the TV has to be plugged in for a few minutes before the back-light flickers. I can switch the ribbon cable from the right side to the left and then the right side does the flckering, so it appears that both LED strings are not shorted. (bottom of panel 1st pic by the red indicator led)



                    The C board is green and appears to be exactly the same board as the A board.



                    The original board is tan with burn marks on the back. I had no PS voltage at all with this board installed. Hence the reason I ordered the new board.



                    In general, I have had good luck with buying boards off of eBay. I can not find the right board for this set, and I am not sure what panel should match to the A or C boards, but I ass-u-me,at least the leds should light up.
                    Attached Files
                    Last edited by electicman; 03-01-2019, 05:13 PM.

                    Comment


                      #11
                      Re: Westinghouse LD3255VX Main Board eBay replacement.

                      Originally posted by Kg74 View Post
                      To work on the chip I first tried hot air, but it tore up the pads and blew some smds around. In the end I put a fat tip soldering iron on the bottom of the board, and blew hot air from above and the chip was easy to remove. I fashioned a copper heat shield to protect the surrounding areas. I had my original board to learn from - which in the end I completely destroyed. So I am trying to save you from the same mistakes.

                      Clean up the area well, and use solder paste for the new install.
                      I was wondering this. The datasheet shows a pin33 / gnd which appears to be a metal pad on the bottom of the 34844. I swear they make these boards sooo freaking hard to fix without destroying the board that you have to be pretty dedicated at saving this $40.00 TV.. It truly HAS to be a labor of love, because there isn't any money in it for sure.

                      I only paid 25 bucks for the board with free shipping. It was listed for 55 bucks, but the description said minor cosmetic problems, so I offered 25 and boom, they took it within 10 minutes. When I got it several of the connectors were broken and the latch tab was gone for one led ribbon cable. I managed to rob it off of the old board. Sooo, if I turn it into another paperweight, at least I don't have a lot of money in the new processor.



                      The guy I got it from (STL CL freebies) said he used it as a computer monitor. He said it just went poof one day, never to work again.

                      Considering that I don't own a TV that worked when I got it, I will eventually figure this one out too.

                      Thanks again for everyone's suggestions. Don't for a moment think I am not listening, because I am. I will post updates when I can. I may try to find the short on the old board, but then again.. no schematics, multilayer board, smt technology.. yok. lol
                      Attached Files
                      Last edited by electicman; 03-01-2019, 05:16 PM.

                      Comment


                        #12
                        Re: Westinghouse LD3255VX Main Board eBay replacement.

                        The 34844 pad to ground is a major pain, that is why I used air on top and heat below. Mine was a labor of boredom and a cold winter.

                        You have two approaches here: 1) try to fix the original board "A" which you know at one time worked or 2) work with board "C" which "allegedly" works.

                        For option 1, you need to put the board back to its original state, if you only played with that one connector - leave it for now and focus on getting one channel to work. It sounds like you have no power at all on this board.

                        You are going to have to start trouble shooting here, looking for shorts and failed components. Here the forum heroes can help - they understand this stuff in ways I do not. My main advise is pick your path and follow all their instructions and suggestions in a timely and exact manner - especially if you pick option 1. Their time is valuable and they actually invest themselves in solving your problem. You cannot disappear for a few days - you have to report back timely or they will lose interest and move one - never to return.

                        For option 2, I would swap over the EEPROM. Take the "A" board EEPROM and move it to the "C" board. I don't think this is the issue, but it takes one thing out of the equation.

                        I have no where near the skill and expertise of other members on this board. Members like Budm really know their stuff. I wonder if they have schematics imprinted on their bed sheets.

                        All I can do is take a VOM to my TV and tell you what kind of measurements I am getting on my working set.

                        For now I would use your Ninja like skills to measure the readings off the pins on the 34844 and post them. I will then compare them to mine. Start by pulling the LED cables and take the measurements on both sides and compare and post, then pick the sorta working channel and connect the cable. I will then compare your reading with what I get.

                        Hopefully the true minds of the forum will help out.

                        To start - pick your direction. Board "A" most likely has a short and/or failed components on the front power side, Board "C" has other possible issues.

                        One last thing, with no power, do as one poster mentioned and check the cable/LED for shorts. You can measure the cable off the connector - leave it all plugged in.

                        Comment

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