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    #41
    Re: Sharp LCD

    Sorry for the confussion. I slowly heated all the caps on that psu. I don't know how to heat just those ones. I guess I could put some cardboard around them and use the hair dryer like some one suggested. I was just trying to see if that was where the problem is. I would just replace them all if I can find them. But then some else sugested that because of the hi voltage they are not likely the bad ones.

    Menessis
    Last edited by Menessis; 01-02-2011, 11:31 PM.

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      #42
      Re: Sharp LCD

      Update.

      I Isolated the hi voltage caps from the others with a folded up newspaper. Then did the hair dryer trick on the others. TV came on before long. So I am going to leave the hi voltage ones as is.

      Order is placed. Got a mixed bag. FM, FR, HE, and a LXZ just for fun.

      Menessis

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        #43
        Re: Sharp LCD

        Originally posted by Menessis View Post
        Order is placed. Got a mixed bag. FM, FR, HE, and a LXZ just for fun.
        For fun, it would be interesting to save the old KY caps. When, if, you get an ESR meter, check out the ESR of those caps. Or give them to someone with an ESR meter?
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          #44
          Re: Sharp LCD

          I'll mail them to you!

          Menenssis

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            #45
            Re: Sharp LCD

            Update! Got my new caps in today. Thats the good news. The bad news is that it still has the problem. So much for my logic!

            I warmed up the right side of the board where all the low voltage caps are and it worked.

            There is only 3 other caps on the board. The two 330uf 220v and the 33uf 350v. I can get them as 'snap in", 3000hours. I could cut the leads on the old ones and solder the new one there??

            But it only takes about 20 to 30 seconds to warm up and work right. (was about 25 minutes before). Another thought, maybe it's due to the fact that it wasn't plugged in.

            Any thoughts?

            Menessis
            Last edited by Menessis; 01-05-2011, 05:36 PM.

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              #46
              Re: Sharp LCD

              LOL I just re-read my last post. What I meant by "not plugged in" is that it was a "cold start". Unplugged and sitting in the corner. Soldered in caps, plugged it in and turned it on right away.

              I have left it off and have tried it again a few times. It starts right up now. Now I am even more confussed.

              Menessis

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                #47
                Re: Sharp LCD

                Originally posted by Menessis View Post
                LOL I just re-read my last post. What I meant by "not plugged in" is that it was a "cold start". Unplugged and sitting in the corner. Soldered in caps, plugged it in and turned it on right away.

                I have left it off and have tried it again a few times. It starts right up now. Now I am even more confussed.

                Menessis
                It sounds like there may still be one thermally sensitive component. It might be in the standby supply, the main supply, the main board, or it even might be a cap that required a little time to re-form the dielectric after having sat in a warehouse for a few years. The real test would be seeing if it will start right up after it's been left sitting plugged in overnight. And if it will also start up properly after it's been sitting unplugged overnight.

                PlainBill
                For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

                Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

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                  #48
                  Re: Sharp LCD

                  Good idea. I will leave it unplugged over night and see what happens. I left it turned off for a few hours and turned it on with no problems.

                  I'm hoping it's "re-form cap" thing myself

                  Menessis

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                    #49
                    Re: Sharp LCD

                    Well bad news. I left this thing plugged in over night and it looks like it is up to its old tricks.

                    Its been on for about 5 minutes now and hasn't straightned out yet.

                    I took it back to the kitchen table and pulled the back off. Plugged it in and turned it on. Quess what. It came on no problems!

                    This makes no sense to me at all.

                    Menessis
                    Last edited by Menessis; 01-06-2011, 10:25 AM.

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                      #50
                      Re: Sharp LCD

                      Update. Does anyone konw what the black Omron relay does. It's just below the row of caps and the large heatsink.

                      I put the tv outside in the cold for 5 minutes. Brought it back in. Plugged it in and there is the problem. Then I heard a click, and it started working right. The only thing that clicks is that relay I'm thinking. Can cold effect a relay?

                      Menessis

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                        #51
                        Re: Sharp LCD

                        I'm thinking bad solder joint. Have you thoroughly inspected the solder under magnification?
                        36 Monitors, 3 TVs, 4 Laptops, 1 motherboard, 1 Printer, 1 iMac, 2 hard drive docks and one IP Phone repaired so far....

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                          #52
                          Re: Sharp LCD

                          OK I re-flowed the solder on that relay. I then put the power supply in the freezer for 5 minutes. Pulled it out, put it back on the tv, turned it on and it worked right away. OK so I put the whole tv outside for about 5 minutes (it's cold here) and when I tried it, the problem is still there! So this would make you think its not on the power supply at all. I also spotted a couple of tiny red leds on the main board (green). The lower one comes on and stays on when the power cord is plugged in and the other one blinks once the tv is turned on.

                          I hooked up a dvd to it. It was working and then the picture started to go. I tapped the side of the bezel and that set it straight.

                          What a pain in the !!!!!!!!!!

                          Menessis

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                            #53
                            Re: Sharp LCD

                            I dug out that T-Con board and had a look. It's under the Power Supply board. When I warmed up the low voltage caps with the hair dryer I would have warmed up that board too. So starting with a cold tv I warmed up the T-Con board and it seemed to work.

                            I did look close with a large magnefier and didn't see anything that looked bad. I checked both the main board and the power board. Then again I don't know what to look for.

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                              #54
                              Re: Sharp LCD

                              Originally posted by Menessis View Post
                              I did look close with a large magnefier and didn't see anything that looked bad. I checked both the main board and the power board. Then again I don't know what to look for.
                              You could have a "pocket". Think of a air pocket in water. You can't see it above water.

                              Bad solder joints look like

                              http://workmanship.nasa.gov/lib/insp...uirements.html
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                                #55
                                Re: Sharp LCD

                                I'm going to pull the main board off again (green) and re-solder the connector for the wires that go to the T-Con board. Second thought, I looked at it and it's way to small for me to solder.

                                The only things I seen that didn't look good with the solder is about 5 joints still had flux on them.

                                The red arrow is where I put some warm air to get it going. And it worked. Next time I tried "wigling the wires and connectors (Blue arrows). And it worked.

                                I get a picture of it.

                                Cool link BTW!

                                Menessis
                                Attached Files
                                Last edited by Menessis; 01-06-2011, 08:02 PM.

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                                  #56
                                  Re: Sharp LCD

                                  A little confused.

                                  When you say the tv has intermittent problem to start up.
                                  Is the tv turns on every time but you referring only to the problem or symptom from the picture posted on #5?
                                  Last edited by fastvideo; 01-07-2011, 08:31 AM.

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                                    #57
                                    Re: Sharp LCD

                                    OK the tv comes on but it seems like when it's cold it shows the problem in post #5.

                                    After taking the last picture of that cable I put a tie strap on it to hold them all in one place. Since then the tv has been working. I am using it as a second monitor to test it out.

                                    Menessis

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                                      #58
                                      Re: Sharp LCD

                                      Well I spoke too soon. Not even 5 minutes after my last post my display started to "streak" from the top down. All different colours. I just tapped the side and it was fixed! I don't believe this thing.

                                      One thing I did notice is once the problem kicks in the picture is not updated.

                                      Menessis
                                      Last edited by Menessis; 01-07-2011, 04:01 PM.

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                                        #59
                                        Re: Sharp LCD

                                        I haven't had time to tinker with this TV for a while.

                                        Any thoughts of how to go at this thing in a logical order?

                                        Menessis

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                                          #60
                                          Re: Sharp LCD

                                          IMHO it's a physical connection problem (based on heating/tapping making it work) so either a bad solder joint, or a flakey connector.

                                          I'd try to isolate it by tapping with a non-conductive instrument and see if you can narrow down the location. Then inspect/resolder/clean accordingly.
                                          36 Monitors, 3 TVs, 4 Laptops, 1 motherboard, 1 Printer, 1 iMac, 2 hard drive docks and one IP Phone repaired so far....

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