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Gateway FPD2485W - Black screen, no backlighting, menu works...

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    Gateway FPD2485W - Black screen, no backlighting, menu works...

    I've replaced the caps that came with the kit from ebay seller "sghill99".

    This auction specifically -
    http://www.ebay.com/itm/330499791209...84.m1497.l2649

    I tested the fuse at F1 on the ?inverter board? I think it's called. The long green one with the coils. I get continuity through it. I don't know any other way to test it.

    I've marked the caps I replaced on the included pics.

    All rotary/barrel caps replaced aside from the big one-


    replaced caps circled in grey, but not the one circled in red. It's a little bit puffed but the kit didn't come with enough of those apparently -


    Replaced the two caps on here, but notice the circled chip. It looks burned AND gets hot when I power on the monitor. The chip that doesn't look burned does NOT get hot. (I know... I probably shouldn't be touching that board or anything on it with the power plugged in...) I don't have a magnifying glass to take a real close look at it. Running my finger nail across it reveals that it is not smooth, but I can't tell if it's material missing or something stuck on the chip.





    The menu lights come on and it acts just like it should when I turn it on aside from the black screen due to the apparent condition of no back-lighting. I disabled the sound long ago so I don't hear the chime it used to make but I'm fairly certain that's because I disabled it. I shined the LED flashlight on the back of my phone at the screen but couldn't tell if there was a picture. When I hook it to a video signal I hear the USB chime from the OS indicating it detects a device, and the lights change state on the monitor indicating that the monitor detects a signal. Essentially it acts perfectly normal aside from the back-lighting not firing up as far as I can tell.


    Please help . I REALLY like this monitor and don't have the cake to replace it right now. I'm using an old 21" FD Trinitron as a replacement. Admittedly the FD is quite a nice monitor as well , but I miss my wide screen .


    Thanks in advance. If I need to test more components please let me know which ones and how to test (or a link with the info) with an old analog volt meter. I don't have a fluke or anything like that.
    Attached Files

    #2
    Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

    Most capacitor kits are for repairing the power supply board only, if you need the caps for the Inverter and the main board, then you need to get the values and Qty. then you may ask them to sell you extra for other boards beside the P.S board.
    The fuse F1, the pictures do not show clear enough to tell which board the F1 is on. Do you get the 24vdc on one of the connector on the P.S. board?
    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 FPD2485W - Black screen, no backlighting, menu works...

      Yes - I was just working on that - the kit has 12 capacitors the board in the add has 12 capacitors, your power board has 12 capacitors so that suggests if you have put 2 in the logicboard and 2 in the inverter board it just doesnt add up? or you have not replaced 4
      on the power board. If you have used some not in the kit what make were they. Can we assume you replaced like for like values -voltage/uF


      With it all set up and switched on can you measure the voltages on the connectors on the
      power board - the two with the black and red wires. Black probe on a ground screw
      red probe on pins. (gaps in socket)
      Last edited by selldoor; 04-09-2012, 03:40 PM. Reason: test volts
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

      Comment


        #4
        Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

        The kit came with 16 caps... All ?rotary? I think is the right term. The barrel shaped caps. I did replace like for like uf/V.

        12 replaced on the top pic. All except the large one near the center of the board. There are no other rotary style caps on that board.

        Marked in Blue -


        The two grey circled caps replaced in the second pic. The red circled cap is not replaced and is slightly puffed at the end. No residue though.

        The cap that can be seen in the third pic towards the center of the right side is one of two replaced caps on that board.
        Attached Files
        Last edited by M1Combat; 04-09-2012, 03:59 PM.

        Comment


          #5
          Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

          Readings taken with NO video input plugged in. Let me know if I should hook it up to something.



          Aright... The row across the top, with pin 1 being the pin with the red wire on it...

          1. 50V
          2. 50V
          3. ---
          4. ---
          5. 10V
          6. ---
          7. 6V (I assume it's 5.5, but I have an analog and the settings are 2.5/50/250 )
          8. ---


          The row across the right side, again with pin 1 being the pin with the red wire on it...

          1. 10V
          2. 10V
          3. 10V
          4. ---
          5. ---
          6. ---
          7. 6V (Again assuming 5.5, but I just have analog readings...)
          8. ---
          Attached Files

          Comment


            #6
            Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

            The 50V you're reading on two of the pins seem a bit high. How are you taking your readings?

            Comment


              #7
              Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

              Black lead on a ground screw with the red lead on the solder joint just behind the plug. Also... I'm using an old analog meter set to 50V, so maybe it's 48V? What should it be? Knowing I just have an analog I guess I didn't look too closely to see if it was 48 or 50. I assumed It'd be 0V or correctV...

              Comment


                #8
                Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                I don't know what the voltage values should be since I don't have a schematic and none of those connectors appear to be labeled. I'm basing my comments assuming that the caps below that connector are probably rated no more than 25V-35V. Correct?

                As for your meter, if you have it set to 50VDC, then your reading of approx 48V should have the needle on your meter going almost all the way to the right full scale.

                Comment


                  #9
                  Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                  That 50vdc reading does not sound right at all, the highest cap voltage rating for the kit would not be more than 35vdc rating for the large radial caps.
                  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


                    #10
                    Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                    Does that indicate a regulator failure?


                    I did set it to 50VDC and it pretty much pegs the meter. It doesn't peg it instantly like it was 300V or something... but it gets up to what looks to be 50V in a hurry.

                    Comment


                      #11
                      Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                      Just to verify, trace out this 50vdc test point, it should be connected to the positive leg of the filter caps you had just replaced, look at the voltage rating of that cap, if it is not rated higher than 50vdc, then do not try to run the board any more.
                      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


                        #12
                        Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                        Tested it again with VM set to 250V and it looks like ~52V.

                        As far as my untrained eye can tell it looks like the trace goes to the positive side of a 35V radial cap... The one closest to the solder joint. I just checked by looking. Is it safe to set the VM for ohms and test for continuity? I assume not so I didn't .


                        Can the meter be off in its calibration? It's old, cheap and has been knocked around a bit most likely. It's been sitting in my toolbox for a few years just waiting to be used. The battery is fresh though...
                        Last edited by M1Combat; 04-09-2012, 11:59 PM.

                        Comment


                          #13
                          Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                          It looks like it lost the regulation, but that should not happen since there is circuits that detect over voltage and over current so it should have gone into shutdown mode. You may want to do close inspection of all the solder joints to make sure you do not have any solder bridges when the new caps are installed.
                          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


                            #14
                            Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                            Set your meter on ohms and touch the probes together does it zero. Is there a calibration
                            screw? Can you test a car battery or the output from some chargers.
                            Set it to 200v AC and test your mains voltage

                            Can you stop posting pictures in line- it will put some members off looking at your thread.
                            Please upload pictures using attachment function when ask for help on the repair
                            http://www.badcaps.net/forum/showthread.php?t=39740

                            Comment


                              #15
                              Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                              There are no solder bridges. Will test/calibrate the VM now.


                              Thanks for the tip about in line pics.

                              Comment


                                #16
                                Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                                I just look at the pictures again, the board only has one transformer fro all 3 voltages, which will not make sense to have one winding voltage way off and the other two windings are OK since they are all based on the turn ratio of the transformer which is coupled through the same primary winding. I think there is an error in voltage measurement some where.
                                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


                                  #17
                                  Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                                  There was a screw on the VM... I adjusted so it was dead center at 0V. Wasn't more than .020" off anyway. Just a hair to one side. When I set to ohms and touch the leads it pegs. I re-measured the V and got pretty much the same readings but not exactly. Dropped to ~48 for the 50V lines, about 9V for the 10V and a little under 6V for the others...

                                  Where would the V measurement error be? I've placed the - lead on a ground screw and the + on the solder joint on the back side of the plug.

                                  Let me go see what the AC mains reads at...

                                  Comment


                                    #18
                                    Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                                    OK... so the VM reads 205V on the mains. That was just a regular wall plug. Not a 220V dryer plug or anything.

                                    What now? Sorry for my apparent lack of preparedness. I thought I posted the topic fairly well prepared for a non-EE .

                                    Comment


                                      #19
                                      Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                                      Originally posted by M1Combat View Post
                                      OK... so the VM reads 205V on the mains. That was just a regular wall plug. Not a 220V dryer plug or anything.
                                      If your analog multimeter is a Simpson or AVO, then it might be worth repairing. Otherwise, I suggest it is time to get a new digital multimeter.
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                                      Comment


                                        #20
                                        Re: Gateway FPD2485W - Black screen, no backlighting, menu works...

                                        Lol...

                                        It's a "Sunpro by actron III" CP7848.


                                        Well crap. Have I been able to give ANY useful info as to what may need replacing and/or repairing?

                                        Comment

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