Sanyo DP46840

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  • kevinm34232
    Badcaps Legend
    • May 2012
    • 1884
    • USA

    #41
    Re: Sanyo DP46840

    Yes I did that earlier:

    OK so going thru the service manual it shows 4 power failure circuits to check:

    IC 1630 I'm getting a steady 3.1vdc not 3.3, is that an issue?

    Audio.Pow IC1670 is where I think the problem is, gets 24v in, but out is sporatic, winds up at about 3vdc before shutdown.

    IC 1660 is good, 9v

    and 12V supply is good.
    Had 3.1vdc at IC1630 instead of 3.3v
    and also erraric readings and Audio Pow

    So what can I check at about that low voltage at IC1630?

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #42
      Re: Sanyo DP46840

      The switching buck converter IC1630 LV5803M (PAGE 45) can take input from 4.5V ~18V and should maintain the output voltage as determined by the resistors (see spec). So it looks like it is not working properly at this point. Its internal reference voltage may be bad.
      I would try a new IC or some sort of 3.3V external power source.

      So far I cannot find that 12V regulator that convert 24v to 13v for the audio section as mention on the link.
      Attached Files
      Last edited by budm; 06-09-2012, 11:52 PM.
      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

      • selldoor
        Slow Learner
        • Dec 2010
        • 7870

        #43
        Re: Sanyo DP46840

        Originally posted by budm
        So far I cannot find that 12V regulator that convert 24v to 13v for the audio section as mention on the link.
        Do you mean cant find the data sheet?

        Is this any help?
        Attached Files
        Please upload pictures using attachment function when ask for help on the repair
        http://www.badcaps.net/forum/showthread.php?t=39740

        Comment

        • kevinm34232
          Badcaps Legend
          • May 2012
          • 1884
          • USA

          #44
          Re: Sanyo DP46840

          Will this work for that IC1630 or no? It says 5v output.

          http://www.mouser.com/ProductDetail/...52bNuFsA%3d%3d

          One other interesting thing that makes me think the audio IC is (or atleast part of) the problem: Normally when I turn TV on, it takes about 10 seconds for power failure circuit to shut down. But when I put my DMM on the audio IC to read voltage, the TV shuts down much quicker, around 5 seconds.

          Comment

          • selldoor
            Slow Learner
            • Dec 2010
            • 7870

            #45
            Re: Sanyo DP46840

            If you check the data sheet for that product at mouser you will see it is the same as
            Budm posted above - so I guess it will be ok. Can you do the external source test before you order - just thinking of postage and minimum order charges, if they apply. My question as I dont know the answer would be can it be more than 3.3v as 3.6v is easier to come by.
            Please upload pictures using attachment function when ask for help on the repair
            http://www.badcaps.net/forum/showthread.php?t=39740

            Comment

            • kevinm34232
              Badcaps Legend
              • May 2012
              • 1884
              • USA

              #46
              Re: Sanyo DP46840

              Are you saying to get an external source of around 3.3v dc and apply it to the output pin of IC? Gonna need some more info on how Id do this please.

              Comment

              • budm
                Badcaps Legend
                • Feb 2010
                • 40746
                • USA

                #47
                Re: Sanyo DP46840

                @selldoor, I mean the location in the service manual, prints are so small.
                @kevin, on the link, the guy cut the 12v traces that feed the amplifier, I do not think you will want to do that unless you are confident in doing it. I will have to locate that circuits section in the manual first, my eyes are real bad right now.
                For the 3.3V power supply problem, you will have to remove some parts from that 3.3V power supply to be able to inject the external 3.3V into it.
                Last edited by budm; 06-10-2012, 12:41 PM.
                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

                • kevinm34232
                  Badcaps Legend
                  • May 2012
                  • 1884
                  • USA

                  #48
                  Re: Sanyo DP46840

                  I feel confident in doing it Im just wondering if the audio IC problem is causing the low voltage on IC1630 or vice versa. Like I said when I test voltage on the audio IC it makes the TV shut down faster like it's adding more of a load or something, I dunno it's just a guess. Is it possible that one circuit is affecting the other?

                  Comment

                  • selldoor
                    Slow Learner
                    • Dec 2010
                    • 7870

                    #49
                    Re: Sanyo DP46840

                    Kevinm, please can you post a link to the Service manual
                    Please upload pictures using attachment function when ask for help on the repair
                    http://www.badcaps.net/forum/showthread.php?t=39740

                    Comment

                    • kevinm34232
                      Badcaps Legend
                      • May 2012
                      • 1884
                      • USA

                      #50
                      Re: Sanyo DP46840

                      I tried to post it it yesterday, it kept failing, I can email you like I did Budm.

                      Comment

                      • selldoor
                        Slow Learner
                        • Dec 2010
                        • 7870

                        #51
                        Re: Sanyo DP46840

                        Yes please - I didnt mean upload it using attachments it will be too big for that
                        I just meant put the link in a post like
                        Please upload pictures using attachment function when ask for help on the repair
                        http://www.badcaps.net/forum/showthread.php?t=39740

                        Comment

                        • kevinm34232
                          Badcaps Legend
                          • May 2012
                          • 1884
                          • USA

                          #52
                          Re: Sanyo DP46840

                          I don't have a link someone emailed it to me

                          Comment

                          • selldoor
                            Slow Learner
                            • Dec 2010
                            • 7870

                            #53
                            Re: Sanyo DP46840

                            Ok Got SM Thanks - will see if I can split it up

                            Here are some BIG excerpts for budm.
                            Attached Files
                            Please upload pictures using attachment function when ask for help on the repair
                            http://www.badcaps.net/forum/showthread.php?t=39740

                            Comment

                            • selldoor
                              Slow Learner
                              • Dec 2010
                              • 7870

                              #54
                              Re: Sanyo DP46840

                              SM Split into 3 zipped sections - all need to be downloaded before it will work.
                              Attached Files
                              Please upload pictures using attachment function when ask for help on the repair
                              http://www.badcaps.net/forum/showthread.php?t=39740

                              Comment

                              • mikeknes
                                New Member
                                • Feb 2011
                                • 2

                                #55
                                Re: Sanyo DP46840

                                Originally posted by simplytrini
                                Hi all, hope all is well. I am wondering if anyone here has had success in fixing this model Sanyo. I am having an issue where the the green led turns on but i cannot get the high voltage for the backlights working, the screen is black and I can turn the tv on/off with the remote and power switch but that is about it. the power supply has: 5v, 15v, 12v & 3.3v. however the HV circuit for the backlight is dead. also I know the inverter board works tried it on another set ant it worked. Any thoughts would be great. Thanks
                                I have had 3 of these in shop in last 4 months .all with same problem .turned out to be main board in all three

                                Comment

                                • selldoor
                                  Slow Learner
                                  • Dec 2010
                                  • 7870

                                  #56
                                  Re: Sanyo DP46840

                                  Originally posted by mikeknes
                                  I have had 3 of these in shop in last 4 months .all with same problem .turned out to be main board in all three
                                  And...??? What was the fault???

                                  We tend to try for component level repairs on here - board replacement
                                  when we have given up.

                                  Please can you update your profile with country and mains voltage
                                  Please upload pictures using attachment function when ask for help on the repair
                                  http://www.badcaps.net/forum/showthread.php?t=39740

                                  Comment

                                  • kevinm34232
                                    Badcaps Legend
                                    • May 2012
                                    • 1884
                                    • USA

                                    #57
                                    Re: Sanyo DP46840

                                    I want to give you guys an update here, I've been talking with the guy who did the audio regulator mod on IC1670. He had me cut 2 traces on the actual audio amp IC0001 to isolate it from the regulator and then check voltage on the regulator. The result was voltage was the same, still dropped to <3v instead of 13v, however TV did not shut down. I actually hooked it up and got a picture for the first time. BUT, randomly it will stil shutdown when turning on, it goes further now and backlight comes on, but sometimes will still kick off before video shows. Also, whenever I have my meter on IC1670 to check voltage it shuts TV down, so thinking this is the problem and it's hovering on the cliff now that the amp is disco'd. Obviously I have no audio at this point. So I will try the linear regulator mod and see what happens. Not sure Ill be able to repair those cut traces but oh well, I have surround sound if not

                                    Comment

                                    • tom66
                                      EVs Rule
                                      • Apr 2011
                                      • 32560
                                      • UK

                                      #58
                                      Re: Sanyo DP46840

                                      Cut traces are easy enough to repair. Just strip off the copper plating on each end of the trace and run solder or a small wire across it.
                                      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

                                      • budm
                                        Badcaps Legend
                                        • Feb 2010
                                        • 40746
                                        • USA

                                        #59
                                        Re: Sanyo DP46840

                                        I believe the protection circuits also look at 13v to see it is OK or not, I believe it on page 5.
                                        At least you are getting some where now.
                                        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

                                        • kevinm34232
                                          Badcaps Legend
                                          • May 2012
                                          • 1884
                                          • USA

                                          #60
                                          Re: Sanyo DP46840

                                          Yes it does say that it needs 13V for that IC, not sure why TV stays on with 3v, although it gets the 13v for a split second. Lenny's theory is the regulator may not even be able to power the power fail feedback signal..?? Yes getting somewhere I appreciate everyone's help.

                                          Comment

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