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Magnavox 19md357b REPAIRED!!!

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    #1

    Magnavox 19md357b REPAIRED!!!

    Hi all, I searched and found no repair info on this TV so I did some old fashion troubleshooting and found the problem. I hope this will help someone else.

    This is a summarization of the repairs done to the Magnavox 19md357b LCD/DVD TV Combo. These instructions are based on the assumption of the person making the repairs to be knowledgeable of observing safe repair conditions (all repairs must be done with no power applied to any of these circuits - unplugged). In changing these capacitors, the tech would know how to solder and how to identify the proper polarity of caps to be installed. These repairs were for a unit having the symptom of no signal, with signal applied (no change in LED state - red only).


    Removing the casing was not too difficult but separating the screen from the DVD portion first is necessary to do this via the small access flap that will reveal 4 small fragile connectors. Be careful with all connectors as some are hard to remove but easy to break. Breaking these connectors most often renders the unit to be irreparable.


    After the plastic back casing is removed (about 7 screws total) then with the back exposed, having the connectors towards you, the board on the right hand side is the one that I replaced capacitors on (Green pc board).


    All of the caps listed don't need to be replaced, however knowing of CapXon capacitor's recent history of failures, I'd change all of the ones listed just in case.

    C118 = 10000uF 10V

    C107 = 470uF 25V

    C176 = 100uF 25V

    C102 = 100uF 25V

    C502 = 100uF 25V

    C112 = 1000uF 10V substituted with 16V

    C555 = 220uF 25V

    C175 = 470uF 16V substituted with 25V now

    C117 = 1000uF 10V substituted with 16V now

    C503 = 220uF 25V

    C114 = 330uF 16V substituted with 25V now
    The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

    Tags: None
    #2
    Re: Magnavox 19md357b REPAIRED!!!

    I just fixed the same exact model of these TV for my barber. There's probably a hell of a lot of these out there. Anyone else fix this LCD TV yet?
    Attached Files
    The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

    Comment

      #3
      Re: Magnavox 19md357b REPAIRED!!!

      Hello Dgtech i have repaired various modles of dell and gateway lcd monitors with bad caps and have alot of exsperiance with electronics desodering and sodering could you please name the caps you did replace as so me or someone else wont have to replace all th caps on this model

      My proublem is that the menue will apear channel and wat not for a split second and then dissapear i am assuming it is the caps on this one also but like i said dont want to have to replace them all thanks in advance

      Nascar

      Comment

        #4
        Re: Magnavox 19md357b REPAIRED!!!

        Note: There was a misprint for C 118. It should be a 1000uF 10V cap not 10,000uF.

        From the list above and the attatched photo on this post, I would suggest changing all of the electrolytic caps to the left of the black line except for the 100uF's (see photo).
        Attached Files
        The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

        Comment

          #5
          Re: Magnavox 19md357b REPAIRED!!!

          had a ton of these 6 months after alco sold them as a loss leader.
          replace all the crapxons.

          Comment

            #6
            Re: Magnavox 19md357b REPAIRED!!!

            hey message to Dgtech...new to the board and cant seem to send you a direct text...may be able to help me. /having the same model problem with green vertical line followed by a static sound. then it blinks out for 3-5 second and comes back on....i change two of the 1000u 10 caps that were reading low, but still the same issue. any assist would be great

            Comment

              #7
              Re: Magnavox 19md357b REPAIRED!!!

              I'd change all of the 1000's, 470's, and 330's. If the problem still remains after, post pictures of the boards in question. They may or may not be the same exact boards in the same unit. Sometimes companies have 2 or 3 different builds of the same model number.
              The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

              Comment

                #8
                Re: Magnavox 19md357b REPAIRED!!!

                Thanks for the reply DGtech i havent started the replacement of the caps yet but i will post a message after i have i about caught up to were i can thanks again for the reply

                Also i think i will try and replace all the replace all the crapxons as kc8adu says lol

                And thanks for your input kc8adu much appreciated
                Last edited by Nascar; 10-10-2010, 11:39 PM.

                Comment

                  #9
                  Re: Magnavox 19md357b REPAIRED!!!

                  Where can you buy the replacement capacitors? Thanks!

                  Comment

                    #10
                    Re: Magnavox 19md357b REPAIRED!!!

                    badcaps.net, digikey, mouser, thecapking, ebay. (even though i DO NOT RECOMMEND THE LAST 2)
                    thats where cps can be bought

                    Comment

                      #11
                      Re: Magnavox 19md357b REPAIRED!!!

                      Thanks. I think I will order from this website...much easier!

                      Comment

                        #12
                        Re: Magnavox 19md357b REPAIRED!!!

                        How did it turn out?
                        The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

                        Comment

                          #13
                          Re: Magnavox 19md357b REPAIRED!!!

                          OMG He just finished a little while ago and yes, it works! He changed about 8 caps and then we hooked it up and turned it on. Everything works...and no lines or screeching noise! Thank you to everyone for sharing their knowledge!

                          BTW I discovered that on straight cable (without going through the box) I get one channel of HBO and one channel of Cinemax!

                          Comment

                            #14
                            Re: Magnavox 19md357b REPAIRED!!!

                            I have this model TV 19md357b/37, I assume it is the same model? The problem with this TV, is that it does not show a picture or do anything, initially. Initially is key, because if you actually unplug and then plug it back in, it will actually work after several attempts.

                            I got this TV for $15 bucks at my local Thrift Store as a (Screen doesn't work) "As Is" type of deal. The TV and DVD of the unit does indeed work and work well, it just take a few attempts to get it going.

                            If it is indeed the capacitors, then which one or ones is the culprit of this particular problem? I know you advise changing them all, but as far as my hands on goes, it is better I do little as possible.

                            If anyone has any photos (large HD) showing the capacitor(s), that would be a bonus!

                            Comment

                              #15
                              Re: Magnavox 19md357b REPAIRED!!!

                              I just wanted to thank everyone for the info I found in this thread. Using new capacitors, ordered from badcaps.net, I was able to salvage my tv also. As suggested, I replaced all 11 capacitors, 4 of which were obviously bulging/bursting.
                              BTW... The symptoms this particular tv exhibited were, when powered on...
                              1) No display at all
                              2) Loud screeching, followed by silence
                              3) A loud pop that made you want to unplug it as fast as possible.

                              Thanks again!

                              Comment

                                #16
                                Re: Magnavox 19md357b REPAIRED!!!

                                Originally posted by Dgtech View Post
                                All of the caps listed don't need to be replaced, however knowing of CapXon capacitor's recent history of failures, I'd change all of the ones listed just in case.
                                Well first, congrats on fixing the unit. Of all the products I can think of, combo TV/VCR/DVD units are some of the most obnoxious just to open up and do some in-circuit troubleshooting. In general, whether the unit contains your favorite caps or not, it is a waste of time to start replacing parts based on the manufacturer's label. There are 2 big reasons for this opinion. The first is that it is often very interesting to know which parts have actually failed. The second is that we usually do not have unlimited amounts of time to replace parts that are not faulty. I make an exception to that statement for mission critical applications.

                                Going further, it is common to see a number of faulty electrolytics on a pc board all of the same manufacturer, same value and voltage rating. When I come across this situation, then all of those parts do get pulled and replaced. The reason: the caps have all been subjected to the same heat levels, are the same age and were all produced at the same time. That much is common sense. If you have a couple of bad caps, and the others are working perfectly well, take notes, replace the bad parts and get on with your life. Just because the part is made by manufacturer X doesn't mean it will go bad while you watch. Part two is that if you actually know which parts fail, there may be some interesting information about special circuit problems that will be a big help in the long run.

                                We all know that bad electrolytics cause lots of electronics nightmares, and that the ESR meter is your friend. But not every electronic problem is caused by bad capacitors - that would be boring, wouldn't it?
                                Is it plugged in?

                                Comment

                                  #17
                                  Re: Magnavox 19md357b REPAIRED!!!

                                  My statement to change all of those capxon's listed (from a year ago) was aimed to all who try to repair this TV set. This advice really isn't for the techs that already know how to troubleshoot. This advice really isn't to teach someone how to troubleshoot. It's simply advice to help someone with the same exact set, with the same exact syptoms, to get the set working. Not everyone has the proper test equipment to troubleshoot every component.

                                  Seeing as you are new, as you learn how to navigate this forum, you will see many posts of praise from people who were able to get their set working. Some end up going a little bit further and fixing other's sets with the valuable information people have shared here throughout the years. The goal here is an ongoing process of continuing to create a kick ass wealth of knowledge - not to criticize the methodology or lack of education of others. If you will be a part of this site, I'd hope you could join in to contribute something more than just being a critic. If you are just a critic - "That would be boring, wouldn't it?"
                                  The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

                                  Comment

                                    #18
                                    Re: Magnavox 19md357b REPAIRED!!!

                                    If you have an ESR meter then you can cherry pick what caps to change.
                                    [Although in the case of Capxon (and the likes) that would be rather foolish.]

                                    Given that most people don't have an ESR meter (or a capacitance meter for that matter) the best advice to hand out is to replace all suspect caps.
                                    .
                                    Mann-Made Global Warming.
                                    - We should be more concerned about the Intellectual Climate.
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                                    Comment

                                      #19
                                      Re: Magnavox 19md357b REPAIRED!!!

                                      I am new here and thank you all so much for posting this it will help me greatly.
                                      I founds this particular Model TV and I am just going to give a shot to make work or not.I usually fix my own Computers have done this since 8 years ago I was giving a Computer by my Uncle may He Rest in Peace. (Cancer)That kind gesture of Him drove to have a Passion of Electronics and Made me realise how life is so important and His Gesture kept me away from the Streets for the rest of my Life now.So I am here to learn more.

                                      Comment

                                        #20
                                        Re: Magnavox 19md357b REPAIRED!!!

                                        Cool. Let us know how the repair went. Any questions along the way, don't be afraid to ask. I dont have all the answers but people are here most of the time with a lot of usefull help.
                                        The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

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