Announcement

Collapse
No announcement yet.

Westinghouse LCM-19W4

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Westinghouse LCM-19W4

    I have a Westinghouse 19" widescreen monitor that I have recapped with United Chemi Con KZE series capacitors, and it is still only partially working. When I first opened it about half of the filter caps were bulged.

    After putting the board back into the monitor and powering it up, I noticed the LCD was displaying the image, but there was no backlight. After that I used another board to power the backlights, and the monitor functioned perfectly (the display board was still being powered via the original board). All four CCFL's were tested individually, and they all lit.

    I have recapped about 20 monitors, with a nearly perfect record. Help me keep it that way. Below are pictures of the front and back of the board.

    The seven brown capacitors on the right are the ones I replaced. I did not replace the two small caps directly above the caution statement about the fuse (starter caps? - they are 50V and 47uF/22uF). There is a hum coming from the Delta transformer.

    Any help is greatly appreciated.

    EDIT: Removed pictures from post to add to managed attachments.



    Attached Files
    Last edited by KyleSTL; 02-06-2012, 08:32 PM.

    #2
    Re: Westinghouse LCM-19W4

    Originally posted by KyleSTL View Post
    I
    I have recapped about 20 monitors, with a nearly perfect record. Help me keep it that way. Below are pictures of the front and back of the board.
    1) For many many reasons, we prefer that pictures are NOT posted inline. If you can, please edit your post with pictures following my sig file below exactly.

    2) Check F200 on the back of the pcb. A good fuse should measure less than 1.0 ohms.

    3) PS. Those are excellent pics.
    --- 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.

    --- end sig file ---

    Comment


      #3
      Re: Westinghouse LCM-19W4

      My apologies, first time I've sumbitted pictures. Please let me know if they are not focused enough. They were quick-and-dirty pictures in bad lighting.

      Comment


        #4
        Re: Westinghouse LCM-19W4

        Originally posted by KyleSTL View Post
        My apologies, first time I've sumbitted pictures. Please let me know if they are not focused enough. They were quick-and-dirty pictures in bad lighting.
        1) Thanks for changing your post. It makes a difference because the regulars participate in about 20 to 30 threads per day.

        2) Check your fuse. I remember this board because someone else (alexanna or jetadm123) spotted that fuse back in 2010 and I have never forgotten about it on this type of board.

        3) If the fuse is good, check those two mosfets on the front of the board. See if they are shorted or not.
        Last edited by retiredcaps; 02-06-2012, 08:46 PM.
        --- 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.

        --- end sig file ---

        Comment


          #5
          Re: Westinghouse LCM-19W4

          Originally posted by retiredcaps View Post
          1) For many many reasons, we prefer that pictures are NOT posted inline. If you can, please edit your post with pictures following my sig file below exactly.
          I disagree. Inline pics are helpful when there is associated commentary.
          sigpic

          (Insert witty quote here)

          Comment


            #6
            Re: Westinghouse LCM-19W4

            OK, all the fuses (250V and the small surface mount ones on the back) have continuity.

            I checked the leads on the two MOSFETs, and one of them had 0.6 Ohm across two of the leads. All the other permutations were discontinuous (all the MOSFET testing with my multimeter was performed with the board completely unplugged, but the MOSFETs still attached to the board).

            I assume this means I will need to replace the MOSFETs to get it working again, correct?

            Comment


              #7
              Re: Westinghouse LCM-19W4

              Originally posted by KyleSTL View Post
              OK, all the fuses (250V and the small surface mount ones on the back) have continuity.
              I don't recommend checking fuses with the continuity feature. Multimeters vary with respect to what they consider "continuous". Some cheap multimeters beep "continuous" for any resistance measurement under 1800 ohms. No fuse is good when the reading is that high.

              A good fuse should measure less than 1.0 ohms.

              I checked the leads on the two MOSFETs, and one of them had 0.6 Ohm across two of the leads.
              Desolder the mosfet and retest out of circuit to verify. If it is still shorted, replace both. Replacements may be at digikey.com or ebay.com.

              With a shorted mosfet, you will not get any backlight.

              PS. Also resolder/reflow the inverter transformer pins.
              --- 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.

              --- end sig file ---

              Comment


                #8
                Re: Westinghouse LCM-19W4

                Thanks retiredcaps.

                My MM reads x.xxx ohms in the continuity setting. They were all < 0.010 ohms.

                I will order Part # IPS135N03LGIN-ND from digikey per the thread about 40T03GP. Thanks again for your help.

                Comment


                  #9
                  Re: Westinghouse LCM-19W4

                  Originally posted by KyleSTL View Post
                  My MM reads x.xxx ohms in the continuity setting. They were all < 0.010 ohms.
                  Just curious what type of multimeter do you have? Some multimeters have a continuity and diode function on the same dial.
                  --- 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.

                  --- end sig file ---

                  Comment


                    #10
                    Re: Westinghouse LCM-19W4

                    I have a couple DMMs, and I believe I was using my Sperry. I could check the model number when I get home. The other one is a tiny Radio Shack model I keep around because it is small and durable, and has the leads permanently attached.

                    Comment

                    Working...
                    X