LC401EM3F Emerson Inverter Issue

Collapse
X
Collapse
 
  • Page of 2
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
  • dcapper
    Badcaps Veteran
    • Dec 2013
    • 496
    • Canada
    #21
    Re: LC401EM3F Emerson Inverter Issue

    Never thought of that. I'll test it this week. I'll follow the 3v pin back through the power supply to see if I have a weak cap.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA
        #22
        Re: LC401EM3F Emerson Inverter Issue

        That 3V signal is routed through the power supply board for clean wiring, the power supply board is being used as the junction point, the signal is generated by the main board and is routed through the power supply board.
        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

          • dcapper
            Badcaps Veteran
            • Dec 2013
            • 496
            • Canada
            #23
            Re: LC401EM3F Emerson Inverter Issue

            Originally posted by budm
            That 3V signal is routed through the power supply board for clean wiring, the power supply board is being used as the junction point, the signal is generated by the main board and is routed through the power supply board.
            OK, There is two main boards on this tv. One is a signal board and one is like a tcon with hdmi outputs. I'll try the battery and see if the backlights come on. I get sound but no pic. When I turn it on, I get 3v at the inverter board but it's only for a second but no light flash from the backlights. I do get 3v for a second with the inverter board disconnected or connected.
            Last edited by dcapper; 08-07-2014, 02:32 PM.

              Comment

              • dcapper
                Badcaps Veteran
                • Dec 2013
                • 496
                • Canada
                #24
                Re: LC401EM3F Emerson Inverter Issue

                After playing with this tv this evening, I decided to meter the other side of the power supply voltages. They are all good for about a second on power up then drop. I hear a funny noise from the lower part of the power supply. I am going to research it further. Maybe a faulty diode I missed.

                EDIT: It was just the sound of the relay losing power. I'm starting to think it's the MIP2F3 chip.
                Last edited by dcapper; 08-24-2014, 10:53 PM.

                  Comment

                  • dcapper
                    Badcaps Veteran
                    • Dec 2013
                    • 496
                    • Canada
                    #25
                    Re: LC401EM3F Emerson Inverter Issue

                    Changed the MIP chip. No change. Changed pretty much everything now. Power supply is too expensive to replace. Not worth it. Maybe a junker in the end.

                      Comment

                      Previous 1 2 template Next

                      Related Topics

                      Collapse
                      • caspian
                        What Zener Diodes on a Linear Power Supply
                        by caspian
                        Dear members,

                        I have a linear variable power supply with unknown brand name that I used for voltage injection.
                        Then it failed. I discovered that its transistors (Q1 and Q2) are shorted.
                        In addition, I discovered that its zener diodes are defective.
                        I can replace the burned transistors.
                        But I do not know the model of the zener diodes. the model number is not marked on the zener diodes.
                        Therefore, I cannot replace the zener diodes.
                        I do not want to test the zener diodes in a test circuit to discover their model or value.
                        no schematics are available...
                        05-26-2025, 12:38 PM
                      • rounin
                        MacBook Air A2337 (820-02016) USB-C Port Issue – Only Works in One Orientation (CC Line Problem?)
                        by rounin
                        Hi everyone,

                        I'm working on a MacBook Air 2020 (A2337, board 820-02016) and running into a strange USB-C issue. I've gone through quite a bit of testing and part replacement, but I'm stuck — hoping someone here can shed some light.

                        🛠 Original Issue
                        The machine initially wouldn't negotiate 20V over USB-C — stuck at 5V.
                        Diagnosis showed PP1V5_UPC0_LDO_CORE shorted to ground.

                        I replaced U3100 (UF400) using a donor board (A2179), and the machine powers on fine now.

                        ⚠️ New Problem: One USB-C Port Only Works in One Orientation...
                        04-19-2025, 01:18 AM
                      • ugamazing
                        Three 820-01700 32GB Logic Boards Same Issue: Won't Wake From Hibernate
                        by ugamazing
                        I have three identical-spec 820-01700 boards (2.6/32/512), and ALL THREE boards came to us with the same fault, from different sources: The boards don't wake from hibernation with the keyboard or lid, they ONLY wake when you press the power button. I understand this is a very minor issue, but the boards must be fixed!

                        We will of course begin with the obvious (checking lid signals), but I couldn't help but notice these three boards were all 32GB variants. Has anyone noticed an issue relating to these 32GB boards in particular? I of course don't think it's a RAM issue, but it's bizarre...
                        12-17-2024, 07:05 PM
                      • Dreadnought
                        L40DIGB20 Logik 40" inverter/backlight issue.
                        by Dreadnought
                        Hi. Firstly I apologise if I break any forum unwritten rules, as I'm new here. I've used badcaps for advice in the past, but I've only just joined. I'm self taught, so I don't have anywhere near the knowledge that some of you guys have, but I can only hope to keep learning and get there one day.
                        Anyway, I've been working on a TV recently. It's the one listed in the title. Logik L40DIGB20. It powers on fine, with the standby light turning blue as it should. The backlight turns on for a second, then goes off. Using a flashlight, I can see an image on the screen. The power supply is fine,...
                        02-08-2021, 12:28 PM
                      • mitsu2k
                        Power-One solar Inverter driving me NUTS!!!
                        by mitsu2k
                        Hello folks, this is a last ditch effort. I thought I would seek your expertise before giving up.. I have been working on this thing for over 2 months and have gotten nowhere. Here is the issue:
                        Inverter powers on and immediately red GFI light comes on and inverter will not complete the initialization process.
                        There is no error code on the screen. I have removed most of the Y capacitors and tested to no avail.
                        All relays are good.
                        I replaced the current transducer- same problem. Checked most of the transistors and diodes and all appear good. I wish I could get my hands...
                        11-13-2023, 07:19 PM
                      • Loading...
                      • No more items.
                      Working...