Announcement

Collapse
No announcement yet.

Lights go out on Westinghouse LCM-19v7

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

    Lights go out on Westinghouse LCM-19v7

    Back at it...This is a like-new 19" LCD Westinghouse LCM-19v7...replaced all 8 of the Capxon caps on the DAC-19M001 P/I board with Panasonic FM's even though they all tested good with low ESR's. Was giving about 10 seconds to powerout and as attached pic shows the left half of screen was vertically srtiped. After repair it all works for maybe 5-10 mins then the backlights start blinking...AND soon its lights out, though green power led stays lit. Turning unit off and right back on restores display but if warm its off in a few secs. If you wait for awhile before cycling power then it stays on longer. Does not seem to come back on itself unless shut down, cooled and rebooted.
    So what do you think...where should I test first guys ?

    ***>BTW Plain Bill is very right about Digi-Key, caps, and shipping. I have done about 10 monitors and just ordered a new batch of 66 Panasonic and Nichicon Caps, and the postage was all of $2.92...heck I even got box in less than 2 days !
    Attached Files

    #2
    Re: Lights go out on Westinghouse LCM-19v7

    Is the problem with the left side of screen fixed?
    I would start on the mins. to black problem with substuting known good ccfl[s]
    Al.
    Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

    Comment


      #3
      Re: Lights go out on Westinghouse LCM-19v7

      If you're seeing the same pic you posted, perhaps reseating the cable to the panel would be helpful. It sounds like there may be 2 issues here; the half screen and the backlights. Consider checking known good ccfls and the windings on the HV transformers.

      Comment


        #4
        Re: Lights go out on Westinghouse LCM-19v7

        The vertical lines however got fixed, BUT the problem is now:

        "After repair it all works for maybe 5-10 mins then the backlights start blinking...AND soon its lights out, though green power led stays lit. Turning unit off and right back on restores display but if warm its off in a few secs. If you wait for awhile before cycling power then it stays on longer. Does not seem to come back on itself unless shut down, cooled and rebooted."

        Comment


          #5
          Re: Lights go out on Westinghouse LCM-19v7

          I see, then I agree with Al and see if you can sub in known good ccfls. If not, then check the primary and secondary resistance of the HV transformers looking for opens or shorts. Keep in mind the resistance can be quite low so be sure your meter can handle that precision. Finally, if the unit is worth it to you, you can always order new ccfls. Many here have used ccflwarehouse and they have been cheap and fast, but there are no doubt other suppliers.

          Comment


            #6
            Re:FIXED>>? Lights go out on Westinghouse LCM-19v7

            This is getting really strange now....after futzing with the cables, the lcd's auto settings, and cycling the unit off, on, and reboot, this 19v7 settled in and I have now run it for 3 different periods a total of 5 hours with no issues at all !
            I've tried tapping the unit, wiggling cables, and resetting its menu but cannot get it to show any sign of failure.
            Did I wake up some component that has been inactive for some years ?
            The work I did was to replace all the caps...and even though I initially saw those veritcal lines on the left side, and saw the backlights blink, and watched the unit go black...all after the repair ...all have vanished and its working like new again.
            ......What do you think happened here ?

            Comment


              #7
              Re: Lights go out on Westinghouse LCM-19v7

              Just like my Samsung on another thread.....the electronics are learning to fear the full weight of the BadCaps forum !

              Comment


                #8
                Re: Lights go out on Westinghouse LCM-19v7

                Seriously, perhaps you improved a connection on the ccfls....it may be temporary....let it cool overnight (or put it outside for 20 seconds!) and try again. You know from all your prior fixes the expansion coefficient of metals and the contraction of them when cold.

                Comment


                  #9
                  Re: Lights go out on Westinghouse LCM-19v7

                  OK Now 24 hours cold and unit wouldn't display at all...it turns green light on then a split second back light flash accompanied by a phzzzzit and led goes amber, does same on cycling or waiting. Does this still sound like lamp connection breakdown, or is it some failing component in the inverter section ?

                  Comment


                    #10
                    Re: Lights go out on Westinghouse LCM-19v7

                    Originally posted by kingofcoins View Post
                    Does this still sound like lamp connection breakdown, or is it some failing component in the inverter section ?
                    Start with post #13 and see

                    https://www.badcaps.net/forum/showthread.php?t=10419

                    Also, check the backside for possibly poor/suspect solder joints (also described in above document).
                    --- 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


                      #11
                      Re: Lights go out on Westinghouse LCM-19v7

                      I did fix a couple solder spots with small holes, but overall quality is very good.
                      I gather my micro-second flash is not the '2 seconds to black', but perhaps a shorting transistor or mosfet ?
                      Does that make more sense as the history after cap repair was it didn't work, then it did for about 4 hours, they after a day off it barely blinks and goes to amber?



                      [QUOTE=retiredcaps;141282]Start with post #13 and see

                      [url]https://www.badcaps.net/forum/showthread.php?t041

                      Comment


                        #12
                        Re: Lights go out on Westinghouse LCM-19v7

                        Originally posted by kingofcoins View Post
                        I gather my micro-second flash is not the '2 seconds to black', but perhaps a shorting transistor or mosfet ?

                        Does that make more sense as the history after cap repair was it didn't work, then it did for about 4 hours, they after a day off it barely blinks and goes to amber?
                        Hmm, a micro second flash would be more of a shorted transistor or mosfet.

                        We will need pictures of your boards.
                        --- 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


                          #13
                          Re: Lights go out on Westinghouse LCM-19v7

                          hi to all ze members..im new here at badcaps.. umm we do things like this: we short ze ref or timing pin of the inverter i.c.this will force ze inverter to work even if there is a problem with the lamps or the transformers.

                          Comment


                            #14
                            Re: Lights go out on Westinghouse LCM-19v7

                            just a quick way to check if the problem is witin ze inverter ..hope it helps..

                            Comment


                              #15
                              Re: Lights go out on Westinghouse LCM-19v7

                              [QUOTE=kingofcoins;141330]I did fix a couple solder spots with small holes, but overall quality is very good.
                              I gather my micro-second flash is not the '2 seconds to black', but perhaps a shorting transistor or mosfet ?
                              Does that make more sense as the history after cap repair was it didn't work, then it did for about 4 hours, they after a day off it barely blinks and goes to amber?



                              Originally posted by retiredcaps View Post
                              Start with post #13 and see

                              [url]https://www.badcaps.net/forum/showthread.php?t041
                              Whoa!!! There are two possible failure modes being described here.

                              'Two seconds to black' is a fault where the inverter controller shuts down due to an error such as too high an output voltage, too high a current through the CCFLs, etc. The description is somewhat misleading because the delay can be less than a second, and can be more than two seconds. In virtually every case, the power LED will stay 'active' - green or blue as long as a valid video signal is present.

                              You seem to be describing another problem - the power LED going to amber even though a video signal is present. That is a totally different problem. For that look to the logic card.

                              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.

                              Comment


                                #16
                                Re: Pics for the Westinghouse LCM-19v7

                                Let me know when we need bottoms too...
                                Attached Files

                                Comment


                                  #17
                                  Re: Lights go out on Westinghouse LCM-19v7

                                  Originally posted by PlainBill View Post
                                  Whoa!!! There are two possible failure modes being described here.
                                  My lack of comprehensive is positively correlated to the amount of holiday cheer over the last 48 hours!
                                  --- 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


                                    #18
                                    Re: Pics for the Westinghouse LCM-19v7

                                    Originally posted by kingofcoins View Post
                                    Let me know when we need bottoms too...
                                    There are a number of voltage regulators on the logic board that you can test. List the part numbers and report the voltage on all pins for all them. U13, U6, U12, U8, and U10.

                                    Not related at all, but on the power board, there are two green picofuses. Check to see if they are open or not.
                                    --- 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


                                      #19
                                      Re: regulator voltages

                                      The pico fuses F200, and F201 both measure about 0.5 +/- ohms.

                                      BTW the readings out of the power to the logic are 3.2v, 5.0v, 20.0vdc

                                      The logic REGULATOR datas...
                                      U6....3.3V, 0.0V, 5.0 VDC part # BA33P 133CB
                                      U8....0.0, 3.2, 5.0 VDC part # AMC 1117 33F0540FJ
                                      U10...0.0, 2.0, 5.0 VDC part # AIC 1084-18PM 783CA
                                      UI2....0.0, 0.0, 0.0 VDC EH11A 539BE
                                      UI3....0.0, 0.0, 0.0 VDC EH11A 539BE

                                      The middle leg of U10 is cut off.
                                      The unit was lighting up for almost 2 seconds with that pzssit while I was running these checks, then back to amber.

                                      Comment


                                        #20
                                        Re: regulator voltages

                                        Originally posted by kingofcoins View Post
                                        The logic REGULATOR datas...
                                        U6....3.3V, 0.0V, 5.0 VDC part # BA33P 133CB
                                        U8....0.0, 3.2, 5.0 VDC part # AMC 1117 33F0540FJ
                                        U10...0.0, 2.0, 5.0 VDC part # AIC 1084-18PM 783CA
                                        UI2....0.0, 0.0, 0.0 VDC EH11A 539BE
                                        UI3....0.0, 0.0, 0.0 VDC EH11A 539BE
                                        According to PlainBill, low dropout (LDO) voltage regulators have a +/- 1% spec.

                                        So U10 is out of spec. It should be 1.8V DC.

                                        U12 and U13 should have voltages on it. In addition, I can't tell from the part number what the LDO output voltage should be.

                                        For U12 and U13 test to see if these are shorted.
                                        --- 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

                                        Working...
                                        X