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Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

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    Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

    I just fixed this Poloroid FLM-3701 TV after it sat on my bench for a week, and thought my experience (which I have repeated several times) would serve as a good lesson for newbies: Never assume a cap is good just because it looks fine. I've gotten caught several times here and it still gets me sometimes LOL.

    All the large filter caps on the outputs had visibly failed. I replaced them all. TV Still did not come up, so I checked the rails. No voltage on any of them. SOoooo, I checked the 120V input, no problems with that. Checked the bridge and large 400V filter cap, no problems. I had a good ~80 Volts after the bridge and filter caps, but Nothing on ANY outputs.

    So I got out my ESR tester and tested every cap on the board. One of the small 22uF 50V caps had a high ESR. I replaced it and viola! The TV powered on.

    So, the lesson I've learned yet again is to ALWAYS TEST ALL the electrolytic caps!!!

    Just thought I'd throw that out there; hope it helps someone.
    Last edited by el3ctroded; 04-17-2012, 12:59 PM.

    #2
    Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

    i realy need to buy a esr tester after reading this. i never realy understood esr untill i found this site i always used to remove each capacitor test the uf etc on my capacitence meter (which does not test esr ) then refit them. i now wonder how many projects i gave up on after testing just the uf etc reading did in fact have bad esr and was the problem i could never track down.

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      #3
      Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

      Good idea, thanks. I will have to check all the capacitors on a Vizio power supply, which has the same symptom after my ESR meter arrives from Russia.

      Comment


        #4
        Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

        If you heat the cap up, the ESR will more likely to go down and the set may start again, taht is one reason to have hair dryer for troubleshooting.
        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


          #5
          Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

          I built an ESR tester and like it far better than the one I bought... It's rather basic, and you don't get the exact ESR value of a cap, but I've found it works well to tell me if the cap is bad... Plus it works great to quickly test fuses.

          Here's the link: http://members.shaw.ca/swstuff/esrmeter.html

          I modified mine slightly to work better with low ESR caps. Once that was done, the trick to read ESR with some accuracy is to short the leads and read the meter. Then use it to read a 1ohm resistor. Once you know where the meter shows short and 1ohm, you can divide the scale up into .1ohm increments

          El3ctroded

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            #6
            Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

            this is the one i am thinking of
            http://www.ebay.co.uk/itm/3208623148...84.m1438.l2649

            Comment


              #7
              Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

              That's quite nice. I googled it and found there's v4.0 out now...

              Comment


                #8
                Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                Yes, don't buy the old one unless you get a significant discount. The maker (RusMike) of the ESR 4.0 is also a member here.

                https://www.badcaps.net/forum/member.php?u=12802
                --- begin sig file ---

                If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

                We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                Please do not post inline and offsite as they slow down the loading of pages.

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                Comment


                  #9
                  Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                  cheers will send him a message later thanks

                  Comment


                    #10
                    Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                    hi sent rusmike a pm regarding buying one no reply as yet though.

                    Comment


                      #11
                      Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                      mine is shipping right now for $75.

                      Comment


                        #12
                        Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                        are you getting the v4

                        Comment


                          #13
                          Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                          yes

                          Comment


                            #14
                            Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                            I have just checked Fedex tracking and my Rigol scope is delivered, yeah.

                            Comment


                              #15
                              Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                              Originally posted by el3ctroded View Post
                              Just thought I'd throw that out there; hope it helps someone.
                              It certainly did!

                              Was given a 2006 model Hanwa 32" model LC-32W18S with similar issues, and after replacing all the large caps I had the same issue as you. Just came across this thread today - found one of the 22uF 50v caps to be high ESR (and low on capacitance) - replaced it and bingo!

                              (my psu was the 667-L37K5-20C variant)

                              Thanks again

                              (and hello to everyone, it's been ages since i've been on the forum!)

                              /bbj

                              Comment


                                #16
                                Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                                That was amazing,,,, I've had this fLM -3701 sitting around forever it seems , could not get it to work ,, I got my ESR meter about four months ago , and it is a time saving fool ,, but HEY , I had replaced all the caps, I saw that were blown, and never thought about that little 50 v 22 uf sucker ,, it's 4:30 AM here , I just was looking for a replacement board for it , and read this thread and wow ,, if that cap didnt come back with a HUGE number ,, wow thanks ,,,,duuhhh ...

                                Comment


                                  #17
                                  Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                                  ty

                                  Comment


                                    #18
                                    Re: Poloroid FLM-3701 Model number 667-L37K5-20A (KAS20) power supply board

                                    I had the same experience with a Polaroid FLM-3701. I took one from the local e-cycle place to play with. It was totally dead. All of the big output caps were swollen. There were three 680uF 25V caps and six 680uF 35V caps. E8 thru E17. I replaced them all and the monitor came to life. But it was intermittent. Sometime it would start and sometime not. I checked the other caps with an ESR meter. There are three 22uF 50V caps on the board. E6, E7 and E22. They all looked good, but tested very bad. I replaced them. A total of 12 bad caps in all. The FLM-3701 now works perfectly.
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