Replacing a bad cap on TV

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • justjoe
    Member
    • May 2013
    • 35
    • England

    #1

    Replacing a bad cap on TV

    I have a 39" LCD TV which has a screen fading problem and using a cheap multimeter ive been able to test half the capacitors and found 1 is bad and figure its worth trying to replace it being so cheap, but the cap is a Samxon 10uF 50v km(m) b4a, thats all the info written on it, and ive been told they are an average brand and sometimes very poor depending on the spec.

    I wanted to ask if its ok to use say Rubycon or Panasonic, and if so how do I make sure I get the exact right spec, or even better could someone point me to an example of an alternative.

    Ive never done anything like this before but im very keen to learn about it, always been interested in electrics and regret not taking a course when i left school.

    Thanks for your advice.
  • Pentium4
    CapXon Be Gone
    • Sep 2011
    • 3741
    • USA

    #2
    Re: Replacing a bad cap on TV

    Of course Rubycon or Panasonic would be a good replacement, I usually use Panasonic FC series for small caps because they are high quality and cheap. How did you determine that the cap is bad, is the capacitance really low on it or is it shorted?

    Comment

    • justjoe
      Member
      • May 2013
      • 35
      • England

      #3
      Re: Replacing a bad cap on TV

      Originally posted by Pentium4
      Of course Rubycon or Panasonic would be a good replacement, I usually use Panasonic FC series for small caps because they are high quality and cheap. How did you determine that the cap is bad, is the capacitance really low on it or is it shorted?
      Interesting thanks, so it sounds like the series determines the quality, I always wondered about that.

      Yes the capacitance is low, its reading 3.7uf instead of 10uf, the other caps im able to test all give a healthy reading so im hoping this cap is the only bad one.

      Another question I have is about buying an ESR meter, I see the price range is either very low or very high, can I get away with a cheap one? do I really need to spend big money for simply testing caps? because this very cheap multimeter seems to be good enough for the smaller caps.

      Comment

      • Pentium4
        CapXon Be Gone
        • Sep 2011
        • 3741
        • USA

        #4
        Re: Replacing a bad cap on TV

        I have a Peak ESR70 (the ESR60 might be cheaper and pretty much the same thing) Capacitance/ESR meter, it should be easy to get there in the UK. All Panasonic caps are very high quality. Low ESR isn't very important with caps like that one that has such a low capacitance

        Comment

        • justjoe
          Member
          • May 2013
          • 35
          • England

          #5
          Re: Replacing a bad cap on TV

          Originally posted by Pentium4
          I have a Peak ESR70 (the ESR60 might be cheaper and pretty much the same thing) Capacitance/ESR meter, it should be easy to get there in the UK. All Panasonic caps are very high quality. Low ESR isn't very important with caps like that one that has such a low capacitance
          wow £100 i was looking at one for £15 lol

          glad you said that about ESR, ive just read about how important it is but the datasheet for this cap doesn't mention anything about ESR. Im going to order the same cap and hope it works and the only bad one then try a better brand if that one goes bad again, being new to this im best playing it safe I guess.

          Thanks for your quick replies guys its been very helpful.

          Comment

          • Pentium4
            CapXon Be Gone
            • Sep 2011
            • 3741
            • USA

            #6
            Re: Replacing a bad cap on TV

            Oh :/ haha... yeah hopefully it's just that cap!

            Comment

            • justjoe
              Member
              • May 2013
              • 35
              • England

              #7
              Re: Replacing a bad cap on TV

              Originally posted by Pentium4
              Oh :/ haha... yeah hopefully it's just that cap!
              I tested the cap about 10 times over 3 days and always got 3.7uf maximum, but now ive removed the cap its reading a healthy 10uf as it should, it seems strange i should get a bad reading so many times, is that normal or is it possible the heat from the solder and pulling it out has somehow fixed it?

              Comment

              • Pentium4
                CapXon Be Gone
                • Sep 2011
                • 3741
                • USA

                #8
                Re: Replacing a bad cap on TV

                I think it's better to test them out of circuit it gives the most accurate reading, it's rare that a cap with such low capacitance goes bad, only 10uF cap I've seen go bad was CapXon and Fuhjyyu. Have you tried soldering it back in to see if it works now?

                Comment

                • truep
                  Badcaps Veteran
                  • Aug 2010
                  • 373
                  • USA

                  #9
                  Re: Replacing a bad cap on TV

                  Look on Ebay for an ESR meter. I just bought one that tests the value and the esr of the cap, as well as diodes and transistirs. It cost around $20-50 USD (depending on which seller. It doesn't haxe a case but that's no problem for me. I did install soft plastic stick on pads to keep it from sliding around. It dorsn' have instructions either but will test caps between TP1-TP2 ,1-3, 2-3. It autodetects the part being tested.

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #10
                    Re: Replacing a bad cap on TV

                    Screen fading problem?
                    Backlight fades or what?
                    Have you checked the power supply outputs?

                    It might not be a problem with the power supply at all.
                    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

                    • justjoe
                      Member
                      • May 2013
                      • 35
                      • England

                      #11
                      Re: Replacing a bad cap on TV

                      Originally posted by Pentium4
                      I think it's better to test them out of circuit it gives the most accurate reading, it's rare that a cap with such low capacitance goes bad, only 10uF cap I've seen go bad was CapXon and Fuhjyyu. Have you tried soldering it back in to see if it works now?
                      No not yet but im about to try it, but im not confident, theres so many components i cant believe ive been that lucky now with this cheap meter.

                      Comment

                      • justjoe
                        Member
                        • May 2013
                        • 35
                        • England

                        #12
                        Re: Replacing a bad cap on TV

                        Originally posted by truep
                        Look on Ebay for an ESR meter. I just bought one that tests the value and the esr of the cap, as well as diodes and transistirs. It cost around $20-50 USD (depending on which seller. It doesn't haxe a case but that's no problem for me. I did install soft plastic stick on pads to keep it from sliding around. It dorsn' have instructions either but will test caps between TP1-TP2 ,1-3, 2-3. It autodetects the part being tested.
                        Yea thanks, I was looking at that last night and £50 seemed a good price to start me off.

                        Comment

                        • justjoe
                          Member
                          • May 2013
                          • 35
                          • England

                          #13
                          Re: Replacing a bad cap on TV

                          Originally posted by tom66
                          Screen fading problem?
                          Backlight fades or what?
                          Have you checked the power supply outputs?

                          It might not be a problem with the power supply at all.
                          Yes the backlight works ok, never had problems with it, but the actual picture would flicker to a darker picture but then eventually fade away, then i press the brighter menu button and the text tries to appear but fades out again very slowly. Now i get no picture at all just a backlight, and i can hear the channel so i still get sound ok.

                          I dont know how to check the power supply outputs no, maybe i should upload a photo so you can see the boards and wires?

                          Comment

                          • tom66
                            EVs Rule
                            • Apr 2011
                            • 32560
                            • UK

                            #14
                            Re: Replacing a bad cap on TV

                            That sounds more like an LCD tab bonding problem. You can attempt to verify if the PSU is at fault by measuring the supply rails. If they're dropping, it's likely at fault, but if they're more or less steady, then it's unlikely.
                            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

                            • justjoe
                              Member
                              • May 2013
                              • 35
                              • England

                              #15
                              Re: Replacing a bad cap on TV

                              Ok i'll go do that then lol just kidding, ive got no idea what any of that means but im gonna go google lcd tab and supply rails and find out but first im gonna solder this cap back on and ive got a lot of other reading to do yet, so much to learn man, thanks for your help guys.

                              Comment

                              • tom66
                                EVs Rule
                                • Apr 2011
                                • 32560
                                • UK

                                #16
                                Re: Replacing a bad cap on TV

                                Do you have a digital multimeter?
                                Black probe on metal chassis.
                                Meter on DC200V or DCV. (Must be a digital meter.)
                                Red probe on the exposed metal around each pin leaving the power supply.
                                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

                                • justjoe
                                  Member
                                  • May 2013
                                  • 35
                                  • England

                                  #17
                                  Re: Replacing a bad cap on TV

                                  Some photos to show you the cap I suspected.

                                  Click image for larger version

Name:	1.jpg
Views:	1
Size:	862.5 KB
ID:	1925160

                                  Click image for larger version

Name:	100_2791.JPG
Views:	1
Size:	789.6 KB
ID:	1925161

                                  Click image for larger version

Name:	100_2788.JPG
Views:	1
Size:	637.1 KB
ID:	1925162

                                  Comment

                                  • justjoe
                                    Member
                                    • May 2013
                                    • 35
                                    • England

                                    #18
                                    Re: Replacing a bad cap on TV

                                    Originally posted by tom66
                                    Do you have a digital multimeter?
                                    Black probe on metal chassis.
                                    Meter on DC200V or DCV. (Must be a digital meter.)
                                    Red probe on the exposed metal around each pin leaving the power supply.
                                    This is the meter, my bro gave it me when he gave up his car audio repair business but i dont think its good enough for the job after coming here and learning about ESR meters.

                                    So is this a digital multimeter? obviously if not then i dont want to risk doing what you just said yet.

                                    Click image for larger version

Name:	$(KGrHqN,!q0FEI1kZSbSBRKlu4wi4g~~60_58.JPG
Views:	1
Size:	36.9 KB
ID:	1925163

                                    Comment

                                    • tom66
                                      EVs Rule
                                      • Apr 2011
                                      • 32560
                                      • UK

                                      #19
                                      Re: Replacing a bad cap on TV

                                      Nothing wrong with that, perfectly adequate for most repairs. TBH most caps bulge when they fail. 95% of them do. However, there's no point shotgunning caps if you don't even know if the PSU is at fault.

                                      For measurements, set the range switch one step left, to the "V=" position.
                                      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

                                      • tom66
                                        EVs Rule
                                        • Apr 2011
                                        • 32560
                                        • UK

                                        #20
                                        Re: Replacing a bad cap on TV

                                        Can we get a close up of this sticker too? We can perhaps look up the panel datasheet from it.
                                        Attached Files
                                        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

                                        • AquaMan Ua
                                          Problem with PANASONIC CF53 laptop after changing BIOS settings
                                          by AquaMan Ua
                                          Hello. I am asking you for a hint on how to solve the problem with my touchbook Panasonic CF53-2 standart model. After setting up the BIOS, the laptop displays the wrong image until Windows loads. (More precisely, it displays, but distorted, instead of the Panasonic image immediately after turning it on, it displays what is in photo #1 in the attached file) Then the image appears when Windows starts loading and then there are no problems with the screen until the reboot. If you enter the BIOS, just a black screen. If you connect an external screen, the image on it is the same as on the built-in...
                                          05-17-2025, 09:40 AM
                                        • Alfieh
                                          NAD C320BEE repair possibly bad capacitors
                                          by Alfieh
                                          hey Im very new to repairing electronics with capacitors as well as using a multimeter so I need so help/guidance fixing this issue

                                          recently I was handed a family members old NAD C320BEE that they had in their loft for storage for a few years but when powered on it went into power safety mode due to a problem on the protection circuit somewhere before it went into storage I was told it worked fine I found lots of people online talking about how the capasitors are known to be pretty bad in this model and can cause this issue the only problem being I don't have much experience sorting...
                                          11-19-2024, 04:55 PM
                                        • Andre Gilbert
                                          Panasonic TC-P55ST50 8 blinks then no blinks
                                          by Andre Gilbert
                                          Hello! yes I know there is already lots of information about this issue. I have a Panasonic TC-P55ST50 that originally displayed an 8-blink error code. Following the troubleshooting flowchart, I ended up replacing the SS board. However, even after replacing it, the issue persists. The TV turns on and stays on without displaying an image, and continuity is confirmed on all connectors. What am I missing here🤔?
                                          Ok Im a mechanical engineer ...but I thought I was able to follow a rather simple flowchart for electric troubleshooting 😂.

                                          TV Model: Panasonic TC-P55ST50
                                          ...
                                          11-20-2024, 08:52 PM
                                        • yuzupatogik
                                          Help with replacing Capacitors on Altec Lansing ATP 3
                                          by yuzupatogik
                                          Hello,
                                          I have this old (2004?) Altec Lansing ATP3 and i would like to replace the capacitors. I have identified 34 out of the 36 of them as Samxon GR of various capacities and voltages.

                                          I can't find datasheets for the Samxon in any of the following variants:

                                          10000uF 25 v - this one i really want to replace because i suspect it is what causes a dull hum regardless of the volume knob position or if the source is plugged in. I am eyeballing the Rubycon 25PK10000MEFCGC18X35.5 for this purpose. So if i pay a 10x the price part for shipping i might as well go ahead and...
                                          02-14-2025, 04:11 PM
                                        • stecos
                                          Panasonic Plasma main board repair (ST30 GT30 VT30 ST50 GT50 VT50),LED with 3 blincks
                                          by stecos
                                          Hi everyone!
                                          I happened several times, in the search for help from the web, to consult this very interesting forum.
                                          So I decided to sign up and I intend to participate actively by making available my knowledge and experience on the subject, I'm a new user but at the same time I'm old in the sense that I have 4 decades of experience in repairing and designing electronics but above all I'm a great passionate about the subject.

                                          Having said that I come to the gist of my post on the forum as the title suggests.
                                          For my passion for technology I'm now collecting several...
                                          11-28-2022, 11:39 AM
                                        • Loading...
                                        • No more items.
                                        Working...