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Gateway FPD2185W inverter or ccfl lights?

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    #1

    Gateway FPD2185W inverter or ccfl lights?

    Hello everybody Ive got a Gateway FPD2185W monitor that displays no picture Flashlight test didn't work. It has a constant blue light when turned on.
    It had bad caps in the power supply which I replaced with Nichicon and United Chemi-Con capacitors. I also replaced the ones on the logic board.
    Still the some problem...

    checked voltages
    5V rail 5.05V
    12V rail 12.03V
    15V rail? 14.4V
    I measured 14.4V on the source pin of mosfets U301 and U304

    I also checked the voltage regulators on the logic board
    voltages were fine

    I checked for shorts across the MOSFETs
    G-S D-S G-D
    U305 14.56M 7.13M O.L
    U302 14.3M O.L 7.8M

    U304 4.72k 12.9M 13M
    U301 4.75k 12M 12.2M


    Checked the transformer windings
    primary secondary
    T301 0.4ohm 160ohm
    T302 0.5ohm 157ohm

    T401 0.4ohm 223ohm
    T402 0.5ohm 222ohm
    T403 0.4ohm 225ohm
    T405 0.5ohm 222ohm
    T406 0.3ohm 220ohm
    T404 0.5omh 223ohm

    checked the states of the BL and N/F pins
    BL=5v
    N/F=0v

    I looked up the part number of the inverter controller I checked pin 6,VDD, and found it was 0.6V hmm...what if I pulled pin 6 to 5V?

    here is a video showing it
    http://www.youtube.com/watch?v=Wfjej...ature=youtu.be

    part number is BIT3193G
    other pins
    1=0v 16=0v
    2=0v 15=0v
    3=0v 14=0v
    4=326mv 13=0v
    5=0v 12=1.17v (should be 1.3v or higher according to datasheet)
    6=283mv 11=0v
    7=0v 10=0.616v
    8=0v 9=0v

    I think its a ccfl issue.
    Please comment any help is appreciated!
    Attached Files
    Tags: None
    #2
    Re: Gateway FPD2185W inverter or ccfl lights?

    Did any one of the lamps even flash for a second?
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment

      #3
      Re: Gateway FPD2185W inverter or ccfl lights?

      no backlights at all

      Comment

        #4
        Re: Gateway FPD2185W inverter or ccfl lights?

        Even with bad or worn out lamps, if the inverter is OK it will try to fire up the lamps, and if the lamps do not stay lit, just take one bad lamp, the circuits will go into shutdown protection mode.
        Power supply voltages are OK, so it can be the logic is not sending the BL_ON to turn on the lamp or bad PWM circuits in the inverter section, need to do some probing.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

          #5
          Re: Gateway FPD2185W inverter or ccfl lights?

          If the BL_On signal is ok, the only other thing that seems odd to me is the Secondary windings resistance on T301 and T302..I have never seen windings less then 450 ohms and usually more than that,but there again have never had this board !1.

          Comment

            #6
            Re: Gateway FPD2185W inverter or ccfl lights?

            Originally posted by hide08 View Post
            I looked up the part number of the inverter controller I checked pin 6,VDD, and found it was 0.6V hmm...what if I pulled pin 6 to 5V?
            You mean pin 10? Pin 10 is Vdd and pin 6 is onoff according to page 3

            Please comment any help is appreciated!
            It is certainly a pleasure to read a well written post #1 with

            - punctuation
            - paragraphs
            - periods
            - homework done
            - video showing the problem
            - clear focused pictures using manage attachments
            - actual voltage readings
            - datasheets attached



            Now for suggestions.

            1) See if pin 10 (Vdd) is shorted to GND (pin 7).

            2) See if you can trace pin 10 vdd to the next component (maybe C323)? See if that component is good or has 5V DC on it.

            3) I recognized the chip PWM (scary) and there are some threads on this forum regarding the BIT3193 if you want to read them and get some ideas.
            Last edited by retiredcaps; 07-27-2012, 01:08 AM.
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            Comment

              #7
              Re: Gateway FPD2185W inverter or ccfl lights?

              Originally posted by Rtech View Post
              I have never seen windings less then 450 ohms and usually more than that,but there again have never had this board !1.
              My working Benq FP71G+ has winding measurements of 200 ohms for all 4 so 160 ohms is possible.
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              Comment

                #8
                Re: Gateway FPD2185W inverter or ccfl lights?

                I seem to be missing something here. What were you doing to get the lamps
                to light up touching 5v wires together? Were you using a separate inverter?
                If the lamps all light why do you think they are the problem?
                Please upload pictures using attachment function when ask for help on the repair
                http://www.badcaps.net/forum/showthread.php?t=39740

                Comment

                  #9
                  Re: Gateway FPD2185W inverter or ccfl lights?

                  Hi again ive gotten some sleep but im back
                  You mean pin 10? Pin 10 is Vdd and pin 6 is onoff according to page 3
                  oops I typed in the wrong pin but I connected the wire to pin 10

                  What were you doing to get the lamps
                  to light up touching 5v wires together?
                  the ccfl controller chip is not getting enough power on, its only getting 0.6v instead of 5v
                  and ISEN is 1.17v, should be higher than 1.3v

                  1) See if pin 10 (Vdd) is shorted to GND (pin 7).

                  2) See if you can trace pin 10 vdd to the next component (maybe C323)? See if that component is good or has 5V DC on it.

                  3) I recognized the chip PWM (scary) and there are some threads on this forum regarding the BIT3193 if you want to read them and get some ideas
                  .

                  ok ill try them out

                  Comment

                    #10
                    Re: Gateway FPD2185W inverter or ccfl lights?

                    Looks like its the logic/video board because there is no image displayed on the monitor using the flashlight test and no output to turn the back-light on from the main IC chip. I can turn on the back-light manually. by apllying 5v to the N/F pin
                    voltages are all fine.

                    The main IC is probably fried.

                    Comment

                      #11
                      Re: Gateway FPD2185W inverter or ccfl lights?

                      Originally posted by hide08 View Post
                      I also checked the voltage regulators on the logic board
                      voltages were fine
                      You don't seem like the kind of person to make this mistake, but since 3 others have in the last 72 hours, do you mind sharing the actual readings results for all 4 voltage regulators along with their part numbers?
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                      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.

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                      Comment

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