Announcement

Collapse
No announcement yet.

Fluke 179 won't tun on

Collapse
X
Collapse
 
  • Page of 4
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 3 4 template Next
    #61
    Re: Fluke 179 won't tun on

    You guys, are really awesome and I'm not.
    I have some visitors(family) for a couple of weeks and I'm not able to work on this, the way I should.
    Sorry about this.
    I try to measure some voltages on the fly, when I have a couple of minutes.
    I have other devices that require my attention, 55" Samsung LED TV, Kenwood DNN990HD nav unit, etc.

    Comment

      #62
      Re: Fluke 179 won't tun on

      Measuring, from pin #98 to pin #100 or from pin #99 to pin #1 I'm getting 0V.
      Last edited by tibimakai; 08-20-2015, 09:46 PM.

      Comment

        #63
        Re: Fluke 179 won't tun on

        It seems like, none of the ICs getting anything. At the top half part, I don't see traces through the board, it's all black.

        Comment

          #64
          Re: Fluke 179 won't tun on

          Found this trace, which to me it doesn't look good.
          It seems like it's going to the negative of the battery.
          Attached Files
          Last edited by tibimakai; 08-20-2015, 11:50 PM.

          Comment

            #65
            Re: Fluke 179 won't tun on

            Originally posted by tibimakai View Post
            Found this trace, which to me it doesn't look good.
            It seems like it's going to the negative of the battery.
            You could ohm that trace to find out if it is good. I would stick with what retiredcaps suggested as he knows the sequence of how the meter's circuits function. So if that trace checks out you will want to find the LDO circuit. You would trace the 9 volt supply line until you come to some regulator that lowers the voltage to the 3.6 volts. I do not know if they would do this with a IC or discrete components or a combination of the two. What ever it appears to be, it will have the 9 volts that are input-ed into it. The idea is to lower the voltage and regulate it so when the battery starts to decrease it maintains the same 3.6 volts DC
            Last edited by keeney123; 08-21-2015, 12:25 AM.

            Comment

              #66
              Re: Fluke 179 won't tun on

              Originally posted by keeney123 View Post
              This is the best I can touch up of the picture for you retiredcaps.
              Good effort, but this is what I expect. From the eevblog 179 teardown thread, this photo shows what is needed in terms of focus, clarity and readability. My only wish is that it is a bit higher resolution to make it easier to read some of the smaller print and that it is shot directly over top.

              https://lh4.googleusercontent.com/-3...h572-no/15.JPG

              Here I can clearly see that PCYI is a 5V LDO made by Texas Instruments. A few more searches, I found this application report entitled "Interfacing the 3-V MSP430 to 5-V Circuits". It gives a number of suggestions on how to convert 5V down to the 3V needed by the MSP430.

              https://cdn.badcaps-static.com/pdfs/...26c30b52eb.pdf

              Just to the left of PCYI pin 1, is a via hole. Just to the left of the PCYI pin 5 is another via hole. Assuming both are pins are connected to their respecitve via hole, if you turn the pcb around these vias will have tracks. Tracing these tracks will show where they go.

              There are also 5 other major ICs on the same side as PCYI. Get the datasheet for each IC and check to see if VCC/VDD exists. Note the min and max for each IC wrt to VCC/VDD. Some might require 5V which is why the PCYI is used and not some other LDO that drops it directly to 3V? This will also help track down possible broken traces and vias. Continuity, with a reading of less than 1 ohm, is your friend when checking the vias and tracks.

              As I mentioned there are at least 3 revisions of the 179 that I know of. The earliest ones didn't even use the MSP430!
              Attached Files
              Last edited by retiredcaps; 08-21-2015, 01:03 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

                #67
                Re: Fluke 179 won't tun on

                That trace is broken. Via is filled with oxidation as well.

                Comment

                  #68
                  Re: Fluke 179 won't tun on

                  Good effort, but this is what I expect. From the eevblog 179 teardown thread, this photo shows what is needed in terms of focus, clarity and readability. My only wish is that it is a bit higher resolution to make it easier to read some of the smaller print and that it is shot directly over top.

                  https://lh4.googleusercontent.com/-3...h572-no/15.JPG

                  So is that the IC in the Lower left corner?

                  Comment

                    #69
                    Re: Fluke 179 won't tun on

                    he ltpz is a regulator

                    Comment

                      #70
                      Re: Fluke 179 won't tun on

                      That was made, with a USB microscope to show the broken trace inside the PCB.
                      The rest won't show, because if I look through the board is all black.
                      Only around the selector switch, is "see through".
                      Last edited by tibimakai; 08-21-2015, 01:20 PM.

                      Comment

                        #71
                        Re: Fluke 179 won't tun on

                        even If you used a high intensity light in the back and then you your USB microscope.

                        Comment

                        Previous 1 2 3 4 template Next
                        Working...
                        X