Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • johnboy1313
    Badcaps Legend
    • Nov 2012
    • 1959
    • USA

    #1

    Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

    I found part of an LG 42LK450 in the dumpster a while back. It was pretty much complete except for the back cover and the base. I've had it under the workbench for sometime. I recently discovered that the base from a 42LM3700 that I parted out fit this model too so that sparked a little more interest. Yesterday, I was bored so I decided to play around a bit. I determined that the PSU and inverter were good but the main board was bad. Not wanting to drop $75 on a main when I don't have the back cover seems foolish. Looking at the main from the 42LM3700 that I parted out, it looked like the board would mount to the back of this panel and most of the connectors were the same with the exception of the connector for the touchpad and IR board. The original main has a 15 pin connector. The new main, only ten. Ten of the fifteen wires were the same color. I pulled those ten out of the plug and put them into the ten pin plug that I pulled off of the other harness. The TV works now. It seems like everything works except the red LED doesn't turn blue anymore. Looking at the attached schematic, it looks like pins 11 and 12 handle that function. Pin 13 is ground. What are pins 14 and 15? I don't know what S/T_SCL or S/T_SDA mean.

    Here's a link to the original mainboard. http://assets.shopjimmy.com/media/ca...8816-top_1.jpg


    Here's a link to the 42LM3700 mainboard.
    http://assets.shopjimmy.com/media/ca...237503-top.jpg
    Attached Files
  • johnboy1313
    Badcaps Legend
    • Nov 2012
    • 1959
    • USA

    #2
    Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

    Here's a picture of the harness after surgery.
    Attached Files

    Comment

    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK

      #3
      Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

      SDL/SCL is I2C bus. Possibly for some kind of processor on that board.
      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

      Comment

      • johnboy1313
        Badcaps Legend
        • Nov 2012
        • 1959
        • USA

        #4
        Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

        Interesting, I wonder why it would be on one and not the other. It looks like both lines run to the MICOM chip, IC1002. I Really have no plans for it as is. I'll probably just keep the panel in the event that I find one with a busted screen.

        Thanks!

        Comment

        • johnboy1313
          Badcaps Legend
          • Nov 2012
          • 1959
          • USA

          #5
          Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

          The LM3700 is a 3D TV, page 59 of the service manual for the LK450 says "TI solution RF-3D OPTION"

          Is it possible that the 3D feature will still function?
          Attached Files

          Comment

          • tom66
            EVs Rule
            • Apr 2011
            • 32560
            • UK

            #6
            Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

            Don't know. I2C would be unusual for 3D glasses transmitter. It's not a guaranteed data bus (messages can be delayed or even lost altogether.)
            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

            Comment

            • goontron
              5000!
              • Dec 2011
              • 4108
              • US

              #7
              Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

              Originally posted by tom66
              Don't know. I2C would be unusual for 3D glasses transmitter. It's not a guaranteed data bus (messages can be delayed or even lost altogether.)
              Panny tough books have I2C for the GPS comunocations, so its not that high loss.
              Things I've fixed: anything from semis to crappy Chinese $2 radios, and now an IoT Dildo....

              "Dude, this is Wyoming, i hopped on and sent 'er. No fucking around." -- Me

              Excuse me while i do something dangerous


              You must have a sad, sad boring life if you hate on people harmlessly enjoying life with an animal costume.

              Sometimes you need to break shit to fix it.... Thats why my lawnmower doesn't have a deadman switch or engine brake anymore

              Follow the white rabbit.

              Comment

              • tom66
                EVs Rule
                • Apr 2011
                • 32560
                • UK

                #8
                Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

                Originally posted by goontron
                Panny tough books have I2C for the GPS comunocations, so its not that high loss.
                It's not that, more because the timing is not deterministic. GPS modules don't need deterministic timing (you don't really care if the GPS updates 9 or 10 times a second in most cases.) 3D glasses need deterministic timing down to milliseconds which I2C struggles to provide.
                Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                Comment

                • johnboy1313
                  Badcaps Legend
                  • Nov 2012
                  • 1959
                  • USA

                  #9
                  Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

                  Is it possible that S/T_SCL and S/T_SDA are used to turn off the red standby LED and turn on the blue power LED? The red LED doesn't flash or shut off at any point.
                  Last edited by johnboy1313; 03-09-2015, 09:20 AM.

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #10
                    Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

                    Originally posted by johnboy1313
                    Is it possible that S/T_SCL and S/T_SDA are used to turn off the red standby LED and turn on the blue power LED? The red LED doesn't flash or shut off at any point.
                    Yes, possibly if there's a microcontroller on that board. But it looks like LED_R and LED_B are available on that connector, so I'm not sure.
                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                    Comment

                    • johnboy1313
                      Badcaps Legend
                      • Nov 2012
                      • 1959
                      • USA

                      #11
                      Re: Frankensteined LG 42LK450/42LM3700: On mainboard, what is SDL and SDA?

                      Thanks guys.

                      Comment

                      Related Topics

                      Collapse

                      • cheeky2
                        Is it possible to upgrade from a Vestel 17MB97 main board to a 17MB110 Main board?
                        by cheeky2
                        I suppose the real question is whether the existing pinouts from ether a 17IPS71 psu are cross compatible with a 17IPS12 psu? If they are then the exchange of the main boards should have no issues providing the screen is compatible with both main boards. Obviously you can change the screen configurations easily enough (providing you have the correct files) for the main board. Why may you ask would I do this? Well a lot of the smart features are no longer working on a Hitachi 48HBT62U main board I wish to give it a new lease of life!
                        Obviously the same LVDS connector for the screen connection...
                        05-25-2024, 03:27 AM
                      • Dani_2024
                        Sceptre U550CV-UMR 4K LED, Bad Caps on Main Power Board?
                        by Dani_2024
                        Hi and thanks in advance for any input you might provide!
                        I have a Sceptre U550CV-UMRD8POTV83BB 4K LED (this is a dumb tv) that I bought new in August 2021, so It's just completed 3 years.
                        Main power board model: TP.MS3683.PC821 T-Con board: N4TP546UHDPU2L_BO

                        Last Sunday I was watching a dvd and fell asleep for about half hour, when I awoke the tv screen was black and couldn't get the dvd menu to show, so I changed the input to antenna and had sound but no picture, turned it off. I then got online and found this great site! ....read many troubleshooting tips and this...
                        10-28-2024, 05:06 PM
                      • m4a2t0t
                        Sharp LC-60LE550U Mainboard F905FM06 DUNTKF905WE06TV Main board keeps dying
                        by m4a2t0t
                        What would cause a main board to die when you disconnect AC power to the TV?

                        This is the second board that it has happened with. All I am doing is disconnecting the power cord from the wall and plugging it back in.

                        I replaced the main board because I was not getting a signal on PS_ON when pressing the power button. The PSU was/is still sending its 5v standby signal

                        Thanks
                        03-27-2023, 04:05 PM
                      • Asraf Atb
                        Help Needed: Samsung UE55MU8000 Dead - Possible Main Board Issue
                        by Asraf Atb
                        Hi everyone,

                        Im looking for some advice regarding my Samsung UE55MU8000 TV with main board model BN94-11606C. The TV suddenly stopped turning on and now shows no signs of life at all not even the standby light at the bottom.

                        Initially, I suspected an issue with the PSU, so I took it to a repair center. They tested it and confirmed that the PSU works perfectly, even on other TVs. Based on that, I started investigating the main board.

                        I disconnected the main board from the PSU, and the backlight turned on, which seems to confirm the main board is the issue....
                        01-27-2025, 05:02 PM
                      • JSin21
                        Compatibility of main boards between different variations of samsung MU6100
                        by JSin21
                        Hoping someone here could possibly help. I have a few questions in regards to compatibility with main boards. But I'll give a quick short run down on what's going on first;

                        I have Samsung Smart TV UA65MU6100WXXY version DA01

                        Now years ago it started intermittently playing up after a lighting strike. Lighting hit the block of units i was living in at the time. Ever since that night the TV started having a mind of its own, It would randomly turn itself off or on, and all inputs stopped responding like HDMI, aerial, but USB still worked. Anyway, over the next few months...
                        11-27-2023, 04:54 AM
                      • Loading...
                      • No more items.
                      Working...