Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]

Announcement

Collapse
No announcement yet.

Westinghouse L2046nv

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
    #1

    Westinghouse L2046nv

    Hello everyone, this is my first post. I have 2 Westinghouse L2046NV monitors that I purchased a couple of years ago. The first display went out on me about a year and a half ago. I got online and found some fantastic info on this forum from many other people who were having the same exact problem. I replaced all the suggested caps as well as the blown mini fuse (parts list included in the thread, talk about awesome lol) and I was back in business.
    So anyhow....i play in a band and we have a practice room setup with a bit of gear. My Bassist fires up his amplifier the other day and it trips the circuit breaker in the room (same circuit the monitor was plugged into). When I got the power back on, the monitor was completely out...no flashing light, no power indicator, it just doesn't turn on at all.

    So I open her up thinking that I probably have a blown fuse. I checked with my multi-meter for continuity on all the mini fuses that I could spot in the circuit. as well as the initial fuse where the 110v enters the circuit. As far as I can tell all my fuses are still good. What I did notice was that the 2200uF cap and the 1000uF cap were bulged and leaking. So I ordered a replacement kit that had all of the caps for this board. I replaced those two that looked bad and I am still getting nothing.
    I took the Same board (assuming that this is the the power supply?) out of my other working monitor and put it in the bad monitor and it fired right up so I know that it is something on this board that has gone bad. I unfortunately don't really know where to go from here. I plugged the board up and I can verify that it is getting power beyond the first fuse but from there I have no idea what I should be looking for. I am an electrician for my Day job and have dabbled with some electronics but I really don't have the background to be able to sit down and troubleshoot this.
    Is there really any sense in swapping out the other caps if they aren't visibly damaged? Is there somewhere else in this circuit I should be checking? I am assuming there is at least one transformer in the circuit but I am not even sure what voltage it should be operating at.

    Thanks in advance for any help.
    Attached Files
    Tags: None
    #2
    Re: Westinghouse L2046nv

    Originally posted by Shredasaurus View Post
    I checked with my multi-meter for continuity on all the mini fuses that I could spot in the circuit.
    1) Using continuity to test fuses is not a good test. Here is why. Some multimeters beep "continuous" for resistance readings less than 1800 ohms.

    A good fuse should measure less than 1.0 ohms.

    Is there really any sense in swapping out the other caps if they aren't visibly damaged?
    2) Yes, Capxon makes terrible quality caps and don't last very long. So change out all the remaining Capxon caps. See standard answer below.

    3) However, I suspect your bridge rectifier is shorted. See the component circled in red.

    If you number the pins 1, 2, 3, and 4, measure the resistance between pins 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4. You can do this initially in circuit.

    Any reading less than 30 ohms suggests a short and you should verify out of circuit (i.e. desolder and retest).

    4) --- standard answer, regulars can skip ---

    https://www.badcaps.net/forum/showpo...84&postcount=3
    Attached Files
    Last edited by retiredcaps; 01-13-2012, 06:58 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

      #3
      Re: Westinghouse L2046nv

      Originally posted by Shredasaurus View Post
      I am assuming there is at least one transformer in the circuit but I am not even sure what voltage it should be operating at.
      5) If the bridge rectifier is not shorted, you should get roughly 165 V DC across the big filter capacitor.

      6) On the connector between the power and main/logic board, there is a legend silkscreened on the board. If everything is working properly you should get those secondary DC voltages.
      --- 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

        #4
        Re: Westinghouse L2046nv

        -So after reading the standard answer....a bad capacitor can result in keeping the monitor from powering up at all and not be visibly messed up if it is out of tolerance? I apologize, I am still trying to wrap my head around the capacitors role in the circuit.

        -RetiredCaps thank you for the quick response. I measured 128 V DC across the filter cap so this would rule out the Rectifier correct?

        -I am a little confused by the Pin out legend on the main power board. It has 7 labels on the left side of the connector ......Ground, Ground, +5v, +13.8v, Mute, ADP-, ADL- On but there are 8 pins total. The right side has EVA, GND, DET, 5v+, W-adj, Shut, ADR+, ADL+.....I am assuming that the left label is for the upper level of pins and the Right label is for the lower pins?

        Also, when inspecting where these pins are soldered to the PCB, I noticed 2 components......R104 and R105 (resistors?). R105 has what looks like a 0 printed in the center and R104 looks like it is no longer there......I am trying to get a clear picture but it is super tiny. Thanks again.
        Attached Files

        Comment

          #5
          Re: Westinghouse L2046nv

          Originally posted by Shredasaurus View Post
          -So after reading the standard answer....a bad capacitor can result in keeping the monitor from powering up at all and not be visibly messed up if it is out of tolerance?
          Yes. A single bad capacitor could keep the entire circuit from working.

          I measured 128 V DC across the filter cap so this would rule out the Rectifier correct?
          Your bridge rectifier isn't shorted, but it still could be bad.

          If you are in the USA, 120 V AC mains should be rectified to 170 V DC.

          The formula is 120 x 1.414 = roughly 170 V DC.

          If you are reading 128 V DC, please remeasure and confirm that number.

          If that is the true number, then you have to measure the bridge rectifier for DC voltage. There should be two + and two -. Each should measure about 85V. 85 x 2 = 170.

          PS. I forgot to mention this is all high voltage since you are measuring the hot side. I didn't mention earlier since you said you were an electrican.

          -I am a little confused by the Pin out legend on the main power board. It has 7 labels on the left side of the connector ......Ground, Ground, +5v, +13.8v, Mute, ADP-, ADL- On but there are 8 pins total. The right side has EVA, GND, DET, 5v+, W-adj, Shut, ADR+, ADL+.....I am assuming that the left label is for the upper level of pins and the Right label is for the lower pins?
          Probably.

          Also, when inspecting where these pins are soldered to the PCB, I noticed 2 components......R104 and R105 (resistors?). R105 has what looks like a 0 printed in the center and R104 looks like it is no longer there.
          Yes. R is resistor. 0 is a 0 ohm resistor. It is possible R104 was not ever present.

          See "Reference designations"

          http://en.wikipedia.org/wiki/Electro...e_designations
          Last edited by retiredcaps; 01-13-2012, 09:32 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

            #6
            Re: Westinghouse L2046nv

            As retiredcaps mentioned, you should see approx 165VDC across the large cap. Since you're seeing much less voltage, try checking the bridge rectifier per his directions on post #2, step 3. When performing these tests, make sure the monitor is unplugged.

            Looks like retiredcaps already beat me to the punchline.

            Comment

              #7
              Re: Westinghouse L2046nv

              I'm expecting you will find that the bridge rectifier is fine, but the large (100uF?, 450 Volt) cap is bad. (I am taking you at your word that you put one probe on each leg of the large cap).

              If one diode in the bridge is shorted, it will blow the fuse or take out some other component in the input line.

              If one diode in the bridge is open, the cap will still charge to 167 volts, however it will be receiving only half the input waveform.

              As an exercise to the student, draw a simple bridge rectifier circuit and show the current flow through the diodes for each half wave of the AC input.

              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

                #8
                Re: Westinghouse L2046nv

                Apologies, It was a long day yesterday and I got confused when typing my initial reply. Re-Testing the two pins from the large capacitor I am reading 169 Vdc. Testing the bridge rectifier I get 57.7 vdc between pins 1 and 2...0 volts Dc between pins 2 and 3 , 59vDc between pins 3 and 4 and 169 volts DC between pins 1 and 4.
                I still intend to replace the rest of the Caps today but is there anything else I should check?
                Oh and yes I realize that this is hi-voltage but it never hurts to have a little safety reminder
                Thanks again!

                Comment

                  #9
                  Re: Westinghouse L2046nv

                  Originally posted by Shredasaurus View Post
                  Apologies, It was a long day yesterday and I got confused when typing my initial reply. Re-Testing the two pins from the large capacitor I am reading 169 Vdc. Testing the bridge rectifier I get 57.7 vdc between pins 1 and 2...0 volts Dc between pins 2 and 3 , 59vDc between pins 3 and 4 and 169 volts DC between pins 1 and 4.
                  I still intend to replace the rest of the Caps today but is there anything else I should check?
                  Oh and yes I realize that this is hi-voltage but it never hurts to have a little safety reminder
                  Thanks again!
                  1) with power off and monitor unplugged, try checking diode D107 for shorts.

                  2) with power off and monitor unplugged, check transistor Q102 (mounted on heatsink) for shorts.

                  3) with power on, check voltage across startup cap CE107.

                  Comment

                    #10
                    Re: Westinghouse L2046nv

                    JetAdm123 I replaced the rest of the caps before i saw your reply. So i now have all brand new caps.

                    The components you mentioned....D107 and Q102 they should be on the underside of the board? Having trouble locating them but I probably need to find a magnifying glass.

                    The voltage on CE107....AC or DC?

                    Thanks again for the help

                    Comment

                      #11
                      Re: Westinghouse L2046nv

                      All components are on top of board (see photo) and the silkscreening may be hidden by the white glue. I believe CE107 is a 47uf 50V cap. Measure voltage using the DC scale. See photo for the other components.
                      Attached Files

                      Comment

                        #12
                        Re: Westinghouse L2046nv

                        OK I have my multimeter set on 2k Ohms. When I put my 2 leads on the 2 pins of d107 it reads OL. When I test the 3 pins of Q102 it gives me 0 resistance and continuity between all three (1 and 2, 1 and 3, 2 and 3) etc..I will test the voltage on that cap in a bit.

                        Comment

                          #13
                          Re: Westinghouse L2046nv

                          I am seeing 0 volts DC at CE107.

                          Comment

                            #14
                            Re: Westinghouse L2046nv

                            Originally posted by Shredasaurus View Post
                            When I put my 2 leads on the 2 pins of d107 it reads OL.
                            If you reverse the leads, it should measure between 0.4 and 0.7 V.

                            When I test the 3 pins of Q102 it gives me 0 resistance and continuity between all three (1 and 2, 1 and 3, 2 and 3) etc.
                            Desolder Q102 and verify that you get the same readings out of circuit.

                            If it is still shorted, list the part number of the chip.
                            --- 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

                              #15
                              Re: Westinghouse L2046nv

                              If you reverse the leads, it should measure between 0.4 and 0.7 V.
                              So with no power on the circuit and my meter set to ohms that resistor should read .4 or .7? I am getting 0L no matter which way I orient my test leads.
                              I am going to Desolder Q102 in a bit to re-test.

                              Comment

                                #16
                                Re: Westinghouse L2046nv

                                Originally posted by Shredasaurus View Post
                                So with no power on the circuit and my meter set to ohms that resistor should read .4 or .7?
                                To test diodes, set your multimeter to the diode test position. A good diode should measure 0L one way, and between 0.4 to 0.7V the other way. Remember a diode should only let current go one way and block it the other way.
                                --- 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

                                  #17
                                  Re: Westinghouse L2046nv

                                  Slapping my forehead lol, didn't have my meter set to diode test. Ok so I got OL one way and .485 the other way. So this Diode is good right?

                                  Comment

                                    #18
                                    Re: Westinghouse L2046nv

                                    Originally posted by Shredasaurus View Post
                                    So this Diode is good right?
                                    Yes.

                                    We have a animated gif for

                                    --- 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: Westinghouse L2046nv

                                      Desoldered Q102....with my meter set to 200ohms I am reading 7.5ohms between 1 and 2. 5.6ohms between 1 and 3 and 2.1 ohms between pins 2 and 3.

                                      This is what appears to be printed on the component.

                                      p6nk60zfp
                                      gk24w v6
                                      chn 71.8


                                      Thanks!

                                      Comment

                                        #20
                                        Re: Westinghouse L2046nv

                                        Originally posted by Shredasaurus View Post
                                        p6nk60zfp
                                        Your Fet is definitely shorted. $1.59 at digikey.com

                                        http://search.digikey.com/scripts/Dk...ords=p6nk60zfp

                                        With USPS 1st class mail, it should be less than $3 and you will get it in 48 hours.

                                        I still recommend changing out ALL the Capxon caps on the power board.
                                        --- 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

                                        Previous 1 2 template Next
                                        Working...
                                        X