I315B1-16A issues

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • perette
    Senior Member
    • Mar 2013
    • 71
    • france

    #1

    I315B1-16A issues

    Hello

    I'm looking for some help on trying to repair a LG 32lc46 which shows the 2 seconds to black problem.
    The inverter board has been replaced once and has been working properly for some times but now here are symptoms.
    Two seconds to black. Green led on as normal working.
    During the two seconds a buzz sound is audible from the inverter board and seems to be located or at one of the transformer or the IC U3.
    It's hard to locate it properly and sensing the vibration with my fingers does not makes me feel comfortable.

    If the board is unplugged from the TV and re connected, it will buzz only after 1 seconds restart.

    Caps have been changed, but no more success. I've checked and resolder each transformer and internal resistance seems to be in range of a 4018l.

    The buzz sound occurs with or without ccfl tubes connected.

    Any suggestion?

    Best regards

    Jm
  • dick_barton
    Badcaps Legend
    • Aug 2015
    • 6642
    • Wales

    #2
    Re: I315B1-16A issues

    Have you any photos of your cicuit boards
    Willing to help but I'm no expert.

    Comment

    • perette
      Senior Member
      • Mar 2013
      • 71
      • france

      #3
      Re: I315B1-16A issues

      Hi.

      Here's the board.

      Buzzing noise seems to come from the IC on the right or one of the transformer above.
      No trace of burn anywhere.
      Fuses are OK.

      Best regards

      Jean Marc
      Attached Files

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #4
        Re: I315B1-16A issues

        You need to trim the legs of those caps.
        Are you sure the noise is not coming from the transformer?
        You also need to check the resistance between the Source and Drain pin of those MOSFET's (the 8-pin devices that are for driving the transformers)
        Last edited by budm; 04-23-2018, 10:01 AM.
        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

        • dick_barton
          Badcaps Legend
          • Aug 2015
          • 6642
          • Wales

          #5
          Re: I315B1-16A issues

          You need to trim the excess legs of the capacitors so that they do not short against other components.
          Are any of the transformers hotter than the others alongside?

          Is there any sign of overheating on the underside of the circuit board especially where the transformers are mounted?
          Willing to help but I'm no expert.

          Comment

          • piernov
            Super Moderator
            • Jan 2016
            • 4435
            • France

            #6
            Re: I315B1-16A issues

            https://www.badcaps.net/forum/showthread.php?t=65078

            Had the same inverter. One transformer was dead, this may not be your issue but you should still check resistance of transformer windings to see if one is off.
            OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

            Comment

            • perette
              Senior Member
              • Mar 2013
              • 71
              • france

              #7
              Re: I315B1-16A issues

              Hello.

              Sure I will clean the caps point.

              Thanks for advices. I'll have a look at it.

              I keep you posted.

              Jm

              Comment

              • perette
                Senior Member
                • Mar 2013
                • 71
                • france

                #8
                Re: I315B1-16A issues

                Hello

                I verified resistance of each transformater and there is only one that shows 1010 ohms instead of 1030 for all others. The one is one of my suspects for the Buzzing noise. Could such small difference explain the all behavior?

                No trace of brun not heat

                A newbie question. I've tried test resistance on the mosfet but did not get any reading. How to proceed?

                Jean Marc
                Last edited by perette; 04-24-2018, 02:43 AM.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #9
                  Re: I315B1-16A issues

                  Can you remove the one with bozzing noise and look on the bottom side of the transformer to see if there is any sign of arcing, over heat, etc.? You can also swap its location with another transformer, also inspect the lamp connector pins, may be you are hearing high Voltage arcing.
                  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

                  • perette
                    Senior Member
                    • Mar 2013
                    • 71
                    • france

                    #10
                    Re: I315B1-16A issues

                    Hi

                    So unsoldered them one by one and it ends up by moving the buzz to another transformer.
                    Then I resoldered them swapping their positions.

                    So, if it's not a transformer could if be another component on the board or even the psu?

                    I'm a lost

                    Jm

                    Comment

                    • perette
                      Senior Member
                      • Mar 2013
                      • 71
                      • france

                      #11
                      Re: I315B1-16A issues

                      Hello everybody

                      Back on this topic.
                      I've recaped the psu and checked each transformer.
                      The problem is still there.

                      The inverter board gets 24v.
                      After switching the TV on, I get 2 seconds and then backlight turns off, but 24v is still there.
                      The buzz sound (with little crack) is there as soon as the inverter board switches the light on, not before.

                      Dead inverter board?

                      Best regards

                      Jm

                      Comment

                      Related Topics

                      Collapse

                      • ttmi100x
                        HANNSG Hi221 -- 2 secs to black feat. CCFL flicker & "burn" marks on power board
                        by ttmi100x
                        Greetings everyone,


                        I have a HANNSG Hi221 monitor that exhibits two seconds to black issues (backlight goes off, display is still on as confirmed by shining a flashlight on it) with some additional oddities...


                        The monitor failed on me with a standard "2 seconds to black" some time ago prompting me to initially replace most of the electrolytic capacitors (some of them were bulging/leaking).
                        Things kinda sorta worked for a night, then the problem returned along with some flickering and "buzzing" noises.

                        Upon closer inspection...
                        07-31-2024, 06:36 PM
                      • ohren
                        Original Xbox 1.0 PSU: Foxlink FTPS-0002 Rev. B. — 12 V low, 5 V high — transformer?
                        by ohren
                        Hello!

                        I'm looking at an original Xbox PSU: Foxlink ftps-0002 rev. B. The 12 V output is too low, and the 5 V output is too (?) high. Unfortunately I don't have an oscilloscope but only a DMM for diagnosis.

                        Measured voltages with no load:

                        After rectifier diodes
                        12V: 6.17 V
                        5V: 5.67 V

                        Secondary transformer pins AC measurement (really don't know if this says anything)
                        12V: 2-2.5 V
                        5V: 1.04 V


                        I also have another (working) Xbox psu from Delta. The same measures there, in order, being: 10.79,...
                        03-18-2023, 10:33 AM
                      • twonk9098
                        Lenovo Legion 5 high fan spin turns off after 34 seconds
                        by twonk9098
                        Hi all,

                        I have a Lenovo Legion 5 with a Ryzen 7 series CPU and RTX 3070 GPU. My issue is that it turns on and all seems fine except after a few seconds the fans spin up high and the laptop turns off after 34 seconds.
                        I can get into bios and can even boot and login to Windows however after 34 seconds no matter if Im at the bios screen or booted into Windows it will just turn off.

                        I have managed to run HWmonitor and the temperatures of the CPU and GPU are fine, I can also touch the heatsync which is warm but not hot.

                        I have tried a few new bios but exactly...
                        07-14-2024, 11:19 AM
                      • mikey5791
                        Is it possible for transformer substitution?
                        by mikey5791
                        Hi all,
                        Got this local made DC power supply (12/14V) given free as the transformer has melted. There is no marking or indication to identify what type or rating of transformer used.
                        Fyi,. I had a busted autogate mainboard with transformer with marking 13-0-13 . Is this the 13v dc type transformer?
                        My questions are
                        1. How do i test to see if the transformer is in good working condition?
                        2. Can this transformer (marking 13-0-13) be used to replace the melted transformer on the DC power supply?
                        Hope you guys understand what i was asking. My intention is...
                        11-03-2022, 02:11 AM
                      • dennis_elx33
                        3PHASE STEP-DOWN Transformer in Check
                        by dennis_elx33
                        Hello All,

                        i would like to post an interesting topic regarding 3-phase stepdown transformer which we suspect to cause an overcurrent (138A) which resulted to power tripped off of the HV power supply (80KV output).


                        Problem statement: Power tripped Off

                        Initial Problem: Found 2 IGBT and 2 rectifier diodes shorted (burnt).

                        Action Done:
                        1) Replaced the faulty parts with good spare.
                        2) Measured impedance of the 3phase input lines and found that L2 to L3 has 23.3ohm while other pairs are 51Kohm. This pins will...
                        12-02-2024, 06:52 AM
                      • Loading...
                      • No more items.
                      Working...