hitachi l40c205

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • lrr250r
    Member
    • Sep 2012
    • 45
    • united states

    #1

    hitachi l40c205

    Hello all have a non working hitachi l40c205 that someone was throwning out. Tv originally didn't power on at all. Upon inspecting the power supply(rsag7.820.1673/roh ver f) I found that the glass fuse was blown and the triac at v811 cracked. When I replaced the fuse and plugged cord in v811 threw sparks and the fuse blew again. I picked up what i was told was a re-manufactured power supply off ebay. Now when i plug it in i hear one click(sounds like its coming from power supply). The red power light comes on however the set doesn't power on. I don't have the remote for the set and the power button is the touch setup. Is there a way to turn set on via jumping any connections. Any tests st this point would be helpful before i place it back out on curb... thanks
  • drpj23
    Badcaps Veteran
    • May 2012
    • 528
    • USA

    #2
    Re: hitachi l40c205

    Could you include pics of the power supply and of the outputs using the manage attachments feature, please?

    Comment

    • lrr250r
      Member
      • Sep 2012
      • 45
      • united states

      #3
      Re: hitachi l40c205

      you want pics of the orig as well as the so called reman ?

      Comment

      • drpj23
        Badcaps Veteran
        • May 2012
        • 528
        • USA

        #4
        Re: hitachi l40c205

        Sure, am interested to see the cracked component.

        Comment

        • lrr250r
          Member
          • Sep 2012
          • 45
          • united states

          #5
          Re: hitachi l40c205

          old board







          Attached Files

          Comment

          • lrr250r
            Member
            • Sep 2012
            • 45
            • united states

            #6
            Re: hitachi l40c205

            here is the new board......i did notice that c842 on the new board is blue and doesn't look right to me....its black on the old board.
            Attached Files

            Comment

            • drpj23
              Badcaps Veteran
              • May 2012
              • 528
              • USA

              #7
              Re: hitachi l40c205

              Wow, it looks like it cracked that green varistor.....wonder what caused all that

              Anyways, on the power supply, what are the voltages.

              Now, just to clarify, with the new p/s, it has a red standby light but that's it? Power button does nothing at all? or does it go to a red light?

              That blue cap looks like a plastic film type; it should be fine.
              Last edited by drpj23; 09-26-2012, 06:54 PM.

              Comment

              • lrr250r
                Member
                • Sep 2012
                • 45
                • united states

                #8
                Re: hitachi l40c205

                As soon as it's plugged in the light on front comes on red. I do not have the remote for the tv and all the controls on the set are touch. When i touch where it says power nothing happens at all. I tried programming a few universal remotes with no luck. I'm not sure if the problem is in the power supply or the controls. Can you walk me threw where to test for voltages on the power supply?

                Comment

                • lrr250r
                  Member
                  • Sep 2012
                  • 45
                  • united states

                  #9
                  Re: hitachi l40c205

                  I see some voltage values silkscreened at the connectors.....is that where i should test or are there specific componets you want values on?

                  Comment

                  • drpj23
                    Badcaps Veteran
                    • May 2012
                    • 528
                    • USA

                    #10
                    Re: hitachi l40c205

                    You should have a standby voltage of about 5v on one of those connectors.....but include a pic of the printed legends.

                    This is sounding like a main board fault since that cuts on the p/s to provide power to the rest of the boards.

                    Comment

                    • lrr250r
                      Member
                      • Sep 2012
                      • 45
                      • united states

                      #11
                      Re: hitachi l40c205

                      5v_s 4.77 volts
                      5v_s 4.88 volts
                      both 12v pins as well as both both 5v_m pins show no voltage


                      this is the 14 pins connector from power supply to the main board
                      Attached Files

                      Comment

                      • lrr250r
                        Member
                        • Sep 2012
                        • 45
                        • united states

                        #12
                        Re: hitachi l40c205

                        meter shows no voltage at any of these pins. should be 24,16 and 5 volt values in various pins. all metering done with plugs removed from sockets on power supply.i also don't see any voltage on either side of the glass fuse.
                        Attached Files

                        Comment

                        • lrr250r
                          Member
                          • Sep 2012
                          • 45
                          • united states

                          #13
                          Re: hitachi l40c205

                          wonder if i can remove cracked parts from old board and replace with ones from this board

                          Comment

                          • drpj23
                            Badcaps Veteran
                            • May 2012
                            • 528
                            • USA

                            #14
                            Re: hitachi l40c205

                            Ok that is good. You will not have any other voltages since the power supply is in standby.

                            Your glass fuse is good since you are getting the 5v and has AC not DC going across it.

                            And lastly I would not replace parts from the "new" board. Buy parts from a place like digikey so you are not stuck with two non-functional power supplies.

                            I'll do some research later on that power supply but budm or tom66 can help you faster than I can research. I am very tired lol

                            Oh I do suspect a prob with main so could you please include pics of it.

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK

                              #15
                              Re: hitachi l40c205

                              You want to check SW. If it is changing when the power button is pressed, but the voltages aren't coming up, it points to a power supply problem. If it's not changing, then it points to a main board problem.
                              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

                              • vinceroger69
                                Badcaps Legend
                                • Mar 2012
                                • 6714
                                • uk

                                #16
                                Re: hitachi l40c205

                                Originally posted by lrr250r
                                meter shows no voltage at any of these pins. should be 24,16 and 5 volt values in various pins. all metering done with plugs removed from sockets on power supply.i also don't see any voltage on either side of the glass fuse.
                                it might be worth rechecking for the missing voltages with the plugs connected to the sockets on the power supply.
                                you should be able to use one of the mounting screws as a earth for your meter then test from the top of the connectors just push the red lead in untill it makes contact then note each reading.

                                Comment

                                • lrr250r
                                  Member
                                  • Sep 2012
                                  • 45
                                  • united states

                                  #17
                                  Re: hitachi l40c205

                                  Ill check the voltage while hitting the power button as well as with all connectors plugged in. This set has touch controls on the front. Is there a method of jumping points on that board or main board to see if issue is with board....wish it was standarnd tactile buttons.

                                  Comment

                                  • lrr250r
                                    Member
                                    • Sep 2012
                                    • 45
                                    • united states

                                    #18
                                    Re: hitachi l40c205

                                    Here are some main board pics......ill pull it later and inspect
                                    Attached Files

                                    Comment

                                    • lrr250r
                                      Member
                                      • Sep 2012
                                      • 45
                                      • united states

                                      #19
                                      Re: hitachi l40c205

                                      tom66 what is SW and where would i check it ?

                                      Comment

                                      • tom66
                                        EVs Rule
                                        • Apr 2011
                                        • 32560
                                        • UK

                                        #20
                                        Re: hitachi l40c205

                                        It's on the PSU, pin marked SW. Likely the on/off control.

                                        You may be able to locate the connector for those buttons and find the pins that correspond to the power button, then jumper those to send the signal to the TV.
                                        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

                                        Related Topics

                                        Collapse

                                        • Tynan Dill
                                          Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                          by Tynan Dill
                                          I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                          Upon bringing it home and plugging it up, it showed a standby light.

                                          I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                          The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                          With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                          Assuming...
                                          11-22-2024, 01:46 PM
                                        • PantherDave
                                          Microsoft Surface Pro (5th gen) model 1796 - no power
                                          by PantherDave
                                          Hi all!

                                          I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. 😅

                                          I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
                                          https://www.badcaps.net/forum/troubl...-hardware-devi...
                                          05-29-2024, 02:01 PM
                                        • GLISIT
                                          Asus Probook P5440UF-XB74 power issue
                                          by GLISIT
                                          Hi all,

                                          TL;DR - this laptop is driving me nuts with the oddball power-related behaviors. Appreciate any insight you can provide!


                                          I'm experiencing a power issue on an Asus Probook P5440UF-XB74. Although I've worked with electronics and computers for decades, this is my first attempt at getting into motherboard-level component troubleshooting. Any help the community can provide is greatly appreciated!

                                          A few weeks ago I was using the laptop (on battery power) for a Zoom meeting. The battery was running very low (long meeting) but I wasn't worried about...
                                          01-16-2025, 02:29 PM
                                        • beetle1303
                                          Carver CM-1090 - Power relay clicking on & off, then fuse blown after 20-30 seconds of power cycling.
                                          by beetle1303
                                          I gotten a Carver CM-1090 amplifier from a friend who has kept it in storage for decades. Opened it up, thick layer of dust cumulated everywhere. Vacuumed it semi-cleaned, and blown off as much as possible the remaining dust. This is a 220V version.

                                          On initial powered up with nothing connected - it works with all the lights and button indicator lit up as pressed, etc. I then powered off, connected a CD player into the CD RCA input and powered it on. It seemed to work for a short while and when I turned the volume up and down to see the the VUs works, the power started to clicked off...
                                          01-13-2025, 08:49 PM
                                        • sam_sam_sam
                                          Desoldering gun station modified to use a 18 volt @ 20 amp switching power supply
                                          by sam_sam_sam
                                          I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump

                                          One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy...
                                          03-31-2024, 02:12 PM
                                        • Loading...
                                        • No more items.
                                        Working...