Announcement

Collapse
No announcement yet.

Fluke 87 III display issue

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

    Fluke 87 III display issue

    LCD display shows partial numbers and the bottom pixels never function leaving me guessing with some numbers and the decimal. I have replaced the elastomeric connectors after cleaning the contacts well and no difference. Has anyone experienced this and not have the connectors help? I figured i'd post before i purchase a new LCD panel to see if it works.
    Attached Files
    You Can't Succeed Until You're Willing to Fail
    Tags: None
    #2
    Re: Fluke 87 III display issue

    Originally posted by zacheriaj View Post
    I have replaced the elastomeric connectors after cleaning the contacts well and no difference. Has anyone experienced this and not have the connectors help?
    I haven't heard of a series III faded lcd display, just the original I series.

    Did you replace the elastomeric strip with a grey coloured one or a pink one?

    See below for some tips.

    http://mrmodemhead.com/blog/fluke-8x-faded-lcd/
    --- 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: Fluke 87 III display issue

      I used the OEM Fluke grey replacements and have cleaned all surfaces as instructed. even twice. Not sure what the problem is but i'd like to be able to use my fluke again!
      You Can't Succeed Until You're Willing to Fail

      Comment

        #4
        Re: Fluke 87 III display issue

        Can you take a picture of the lcd when doing a display test? Turn meter off. Hold down (and keep holding it down) and button and all lcd segments should be on. Take clear focused picture and upload.
        --- 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: Fluke 87 III display issue

          Originally posted by retiredcaps View Post
          Can you take a picture of the lcd when doing a display test? Turn meter off. Hold down (and keep holding it down) and button and all lcd segments should be on. Take clear focused picture and upload.
          It seems to be just the bottom row of pixels.
          Attached Files
          You Can't Succeed Until You're Willing to Fail

          Comment

            #6
            Re: Fluke 87 III display issue

            Did you change the 9 vdc battery? Display can have missing sections if voltage is low. But it most likely the display or driver ic

            Comment

              #7
              Re: Fluke 87 III display issue

              There is no service manual for the 80 series III with schematics, but seeing how a 80 III LCD will work in a series I, I think I can assume that the series I service manual can provide some clues.

              Since the bottom segments are not lit properly, I *think* in the seven segment world, that is referred to as 0d, 1d, 2d and 3d? That is "D" as per

              http://en.wikipedia.org/wiki/Seven-segment_display

              Thus on page 98 of the service manual, that would imply H2 or pin 61 is responsible for driving those segments. If I remember correctly, the DCV that you should get is around 3.3V on pins H1, H2, H3 and H4. It might be possible that there is some dirt/debris on H2 that is lowering the voltage?

              You can try measuring the voltage on all 4 pins and see if there is a significant difference? If you have an oscilliscope, you can also look at the waveform.

              https://cdn.badcaps-static.com/pdfs/...13b266aba8.pdf

              As Ltank suggested you can try a fresh 9V battery.

              PS. I will also ping modemhead to see if he has any ideas on this? He would have probably seen this if you had put this in the Equipment Usage, Soldering, Techniques, and Reviews section instead of the TV section?
              Attached Files
              Last edited by retiredcaps; 09-14-2014, 12:08 AM.
              --- 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: Fluke 87 III display issue

                I agree with retiredcaps, something's wrong with the H2 line. In the all-segments-on test, everything on that backplane is missing, but all others are on with good contrast. So probably not a matter of lowered voltage or bad connection, it looks more like no connection at all. Which means either: bad driver in the chip, bad LCD, or a broken connection in-between.

                Try to eliminate the LCD by seeing if you can get some of the missing segments/annunciators to come on with the LCD out of the meter. For example, a 3 to 5Vp-p 50Hz square wave between H2 and S0 should get the "DC" annunciator on. Take care not to damage the conductive traces on the glass with metal bits.

                It doesn't take much signal to operate an LCD, in fact if you ground the backplane or common line (in this case, H2) and then touch the segment lines with your finger, there's often enough mains noise on your body to turn on the segments.

                Comment

                  #9
                  Re: Fluke 87 III display issue

                  Originally posted by modemhead View Post
                  It doesn't take much signal to operate an LCD, in fact if you ground the backplane or common line (in this case, H2) and then touch the segment lines with your finger, there's often enough mains noise on your body to turn on the segments.
                  i've checked the traces on the PCB and they are reading fine. can you further explain testing the panel out of the meter? I just don't want to damage the traces on the panel.
                  You Can't Succeed Until You're Willing to Fail

                  Comment

                    #10
                    Re: Fluke 87 III display issue

                    LCDs segments are like little capacitors, and are driven with a high-impedance low-frequency AC signal. Usually there's enough of a AC mains-induced signal between the end of your finger and earth ground to activate an LCD segment. I've used this as a quick test of LCDs before.

                    If you hold the LCD glass in the light just so, you can see the conductive traces around the edge. Find the H1 connection and touch it lightly with a probe that is connected to earth ground. (Don't use a sharp probe, obviously.) Then run your finger over the other connections and look for some segments to come on, if they do, the test is working. Then try the H2 connection and see if any of the missing segments/annunciators come on. If they do, then the problem must (unfortunately) be the main chip. If they don't, then the LCD must be damaged/defective.

                    Comment

                      #11
                      Re: Fluke 87 III display issue

                      no success getting the dead segments to turn on. Any idea where I can get a replacement display? Cheapest i'm finding is around $35
                      You Can't Succeed Until You're Willing to Fail

                      Comment

                        #12
                        Re: Fluke 87 III display issue

                        Originally posted by zacheriaj View Post
                        Any idea where I can get a replacement display? Cheapest i'm finding is around $35
                        If modemhead and/or others don't have any more suggestions on actually fixing the lcd, you have the following options that I can think of:

                        1) contact ebay seller a-fluke to see if he has 87-III glass lcd for $37 USD ish. He has 87V glass lcd list and it will NOT be compatible with the 87 III.
                        2) sell your 87-III for parts on ebay/craigslist
                        3) sell your 87-III on badcaps.net buy/sell forum

                        https://www.badcaps.net/forum/forumdisplay.php?f=12

                        4) sell your 87 III via PM (I might be interested)
                        5) buy a non working 87-III off ebay and hopefully get good lcd glass as a donor (requires lots of patience and discipline to not overpay)
                        --- 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: Fluke 87 III display issue

                          6) Ask the same question over at eevblog.com/forum. You will maybe find a handful of people who are interested and can help with your topic. Both modemhead and I are members there and usually respond to these type of multimeter repair threads.
                          7) You can also try FlukeNation.com which is Fluke's forum, but the website/host is super slow and there are no Fluke employees who answer or monitor the forum. If you want to see how NOT to do a technical support forum, flukenation.com is an excellent example. :huge massive thumbs down:
                          Last edited by retiredcaps; 09-14-2014, 11:18 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

                            #14
                            Re: Fluke 87 III display issue

                            Great! Thank you very much for the help.
                            You Can't Succeed Until You're Willing to Fail

                            Comment

                              #15
                              Re: Fluke 87 III display issue

                              I have seen somebody, selling some new style lcd contacts on Ebay, they are black.

                              Comment

                              Previous template Next
                              Working...
                              X