Hitachi L40C205 lines in display after Backlight Inverter Repair

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • fharris1977
    Senior Member
    • May 2017
    • 132
    • United States
    #1

    Hitachi L40C205 lines in display after Backlight Inverter Repair

    Hello. I replaced the backlight inverter on this set for a customer and there are lines horizontally and vertically on the display. They show up sometimes I guess depending on the color of the background screen (will include pictures). The customer swears the lines weren't in the screen before the backlight inverter went out. I thought it may be a bad T-con board at first but this set has no T-con board. So if anyone can help, do you think my problem is in the mainboard, the backlight inverter I replaced, the power supply, a cable, or the display (which means the customer is lying or just didn't notice it). What do you think? Thanks in advance.
    Attached Files
    Tags: None
    • petehall347
      Badcaps Legend
      • Jan 2015
      • 4426
      • United Kingdom
      #2
      Re: Hitachi L40C205 lines in display after Backlight Inverter Repair

      what is it like with a tv picture ?

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA
          #3
          Re: Hitachi L40C205 lines in display after Backlight Inverter Repair

          I am having a hard time seeing the symptom on those screen shots.
          For example like this one: https://www.badcaps.net/forum/attach...3&d=1596227528
          The LCD panel has integrated T-CON board so T-CON board is not replaceable.
          Did you try re-seating the LVDS cable?
          Did you try tighten all the board mounting screws?
          Did you try heating/cooling the main board?
          If it is the panel/T-con issue, you will have to get to the Tab bonding/T-con board and try heating and cooling and some pressing probe on that Tab bonding/T-con 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

            • fharris1977
              Senior Member
              • May 2017
              • 132
              • United States
              #4
              Re: Hitachi L40C205 lines in display after Backlight Inverter Repair

              Originally posted by petehall347
              what is it like with a tv picture ?
              Hi. These are photos of it with a ps4 attached. The vertical lines in the HDMI box has now vanished after reseating the lvds connector to the tab board. The vertical lines are affected when I push in on the lvds connector. Don't know if its because of movement of the board causing tabs to move or connector or cable itself. The horizontal lines don't ever go away. I think the vertical lines are panel/tab related and the horizontal lines are caused by another issue. What do you think? I've included more pics of what I'm talking about.
              Attached Files

                Comment

                • budwich
                  Badcaps Legend
                  • Jul 2015
                  • 3097
                  • Canada
                  #5
                  Re: Hitachi L40C205 lines in display after Backlight Inverter Repair

                  someone did a "hand job" on the cabling with a made up cable as opposed to the normal ribbon cable. As a result, this could cause a "timing / impedance" problem with signals to the panel which you are likely seeing.

                    Comment

                    • fharris1977
                      Senior Member
                      • May 2017
                      • 132
                      • United States
                      #6
                      Re: Hitachi L40C205 lines in display after Backlight Inverter Repair

                      I think is the original cable. Just an older LCD set.
                      Attached Files

                        Comment

                        Previous template Next

                        Related Topics

                        Collapse
                        • howardc64
                          TCL 55S425 few horizontal lines, potential failure on both side of panel/buffer board
                          by howardc64
                          All left and right refers to looking from rear of TV (or looking from front with TV upside down)
                          • TV came with vertical bars and no image. Found faulty TVS on left buffer board. Also replaced T-Con (may have damaged the original while hot air removing components, board has slight warp) and have full image but few horizontal lines on the screen. Some of the lines appears to be 2 pixel tall while others are 1 pixel tall.
                          • Disconnecting left and right buffer board potentially reveals problems on both sides with different signals (unless this T-Con require jumper like Samsung FB_TRDY1&3) Fault
                          ...
                          07-24-2025, 05:17 PM
                        • kdaniel
                          Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)
                          by kdaniel
                          As stated by the person I collected the TV from, it just stopped working overnight. However, I still gave it a go to try and repair it.

                          There is a thread on the same TV but with slightly different issues where they had to tape connection points on the ribbon cable, so I want to see if this is repairable by any chance.

                          After bringing it home and plugging it in, the TV turned on with its backlight working but had no picture. After removing the back cover, the first thing I tried is to unplug one of the ribbon cables and the situation is as follows.

                          Left...
                          11-16-2022, 09:23 AM
                        • fharris1977
                          Hitachi L40C205 Backlight Inverter Repair
                          by fharris1977
                          Hello. I have this hitachi with no backlight and it needs this transformer. Does anyone know where this transformer is sold and can please provide a link if so? I have entered the part number with no luck....
                          06-08-2020, 12:00 PM
                        • Stanley1843
                          Screen Display Vertical Multicolor Lines
                          by Stanley1843
                          Hello, I have a screen in where sometimes when I open it pop-up vertical multicolor lines (I would say the most of them are green). If I tun off and turn on the screen the lines dissapear or if I leave open the screen after approximately five minutes the lines gone. I measured the below voltages on the main PCB and on the T-CON board and the voltages are the same when it doesn’t display the vertical lines and when it displays the vertical lines. Also, I cleaned all the connectors very good with IPA. I moved back and forth the connectors and the COF tabs but the vertical lines didn't displayed...
                          06-29-2024, 11:54 AM
                        • Daren87
                          Sony 8K XBR-75Z8H White Screen Vertical Bars Tcon Code. Help Needed🙏
                          by Daren87
                          Hello everyone,

                          I've recently been given a Sony 8k Z8H. It's got a white screen with two vertical black bars. At times it's given me the 5 blink Tcon code. Testing voltage on the Tcon I can see some low or missing voltage. I've done a basic visual check of cables and the COF. Not seeing anything obvious. The original Tcon seemed to have good caps until turning it over. On the bottom I found maybe 10 caps with both sides of the caps shorting to ground. I thought ok these caps and likely other components on the Tcon are shorted so let's try a replacement Tcon. I just received the...
                          08-13-2023, 03:25 PM
                        • Loading...
                        • No more items.
                        Working...