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    Viewsonic VA912b messed up display

    Viewsonic VA912b display is messed up. Just received this monitor today and it plugs in and powers up fine, but the display is messed up. There are no bad lines or anything, but it seems blurry and distorted. Does anyone know where I should start investigating?

    #2
    Re: Viewsonic VA912b messed up display

    A picture might help. Are you using the analog or the digital input? Also check the video refresh rate and resolution.

    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


      #3
      Re: Viewsonic VA912b messed up display

      I tried taking a pic of the screen, but it didn't show the problem very well.
      The refresh rate and resolution are set correctly.
      And i'm using the analog.

      Comment


        #4
        Re: Viewsonic VA912b messed up display

        Viewsonic likes cheap caps in power supply (often Elite brand).
        Signal won't be good with noise in the power.

        .
        Mann-Made Global Warming.
        - We should be more concerned about the Intellectual Climate.

        -
        Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

        - Dr Seuss
        -
        You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
        -

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          #5
          Re: Viewsonic VA912b messed up display

          Originally posted by PCBONEZ
          Viewsonic likes cheap caps in power supply (often Elite brand).
          Signal won't be good with noise in the power.

          .
          Awesome, then I shall open it up tomorrow and investigate the boards.

          Comment


            #6
            Re: Viewsonic VA912b messed up display

            replace these as a starting point
            The three bulging 470uf caps use 470uf 25v for all 3. The big 100uf 400v cap may hava a slight bulge but usualy open circuit sizes 470uf 25v 10mm x 16mm 470uf 10v :8mm x 12mm
            100uf 400v 100uf 400v 18mm x 35.5mm"

            Comment


              #7
              Re: Viewsonic VA912b messed up display

              I investigated the caps and none of them are bulging or leaking. Is it advisable to replace them anyway?

              Comment


                #8
                Re: Viewsonic VA912b messed up display

                You are just at fuzzy screen stage.
                Possible (and likely) cause:
                Degrading caps are letting noise into the power to video section so the video circuits are suffering from 'dirty' power and you get a muddy video signal.
                -
                By the time they bloat you'll probably be having problems even just keeping it on.

                Another possible cause is a bad video cable.
                Does the one you are using have a ferrite (ideally two).
                [see pic of a ferrite on a usb cable]
                I have some monitors that get 'snow' if I don't use a ferrite'ed cable.

                What caps do you see in there?

                .
                Attached Files
                Mann-Made Global Warming.
                - We should be more concerned about the Intellectual Climate.

                -
                Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

                - Dr Seuss
                -
                You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                -

                Comment


                  #9
                  Re: Viewsonic VA912b messed up display

                  Originally posted by Adasm
                  I investigated the caps and none of them are bulging or leaking. Is it advisable to replace them anyway?
                  Yes. Bulging or leaking are very obvious signs of failure. Other problems can be much less obvious. An ESR meter ($70 and up) will help identify failing or marginal caps, but even that isn't an absolute test.

                  I just replaced all the electrolytic caps in a FPD1760 power supply and inverter. Total cost including shipping was about $6. Replacing all the caps took less than half an hour. I gladly spent an extra $5 (and 25 minutes) to be confident I won't have to pull the monitor apart again. This is especially prudent if the caps are a brand that is notorious for failures.
                  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


                    #10
                    Re: Viewsonic VA912b messed up display

                    Originally posted by PlainBill
                    Yes. Bulging or leaking are very obvious signs of failure. Other problems can be much less obvious. An ESR meter ($70 and up) will help identify failing or marginal caps, but even that isn't an absolute test.

                    I just replaced all the electrolytic caps in a FPD1760 power supply and inverter. Total cost including shipping was about $6. Replacing all the caps took less than half an hour. I gladly spent an extra $5 (and 25 minutes) to be confident I won't have to pull the monitor apart again. This is especially prudent if the caps are a brand that is notorious for failures.
                    That is true. If you took the time to ear it apart, recap it before it dies and you have to open it up again and do it anyway. If you want further confirmation, post brand & series of your PSU's caps and that can give more light into this issue.
                    There are 10 kind of people in this world: those that understand binary, and those who don't.
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                      #11
                      Re: Viewsonic VA912b messed up display

                      The brand of caps on the PSU is CapXon.
                      I see: 5x - 470uF 25V
                      1x - 100uF 400V
                      1x - 470uF 10V
                      1x - 22uF 50V

                      These are all the radial caps on the PSU. I can put a pic up tomorrow.

                      Comment


                        #12
                        Re: Viewsonic VA912b messed up display

                        Originally posted by Adasm
                        The brand of caps on the PSU is CapXon.
                        I see: 5x - 470uF 25V
                        1x - 100uF 400V
                        1x - 470uF 10V
                        1x - 22uF 50V

                        These are all the radial caps on the PSU. I can put a pic up tomorrow.
                        The bank of 470uf will be your problem. The 400v one rarely fails. I replace all the 470 with 25v versions
                        There are 10 kind of people in this world: those that understand binary, and those who don't.
                        • ASUS ROG Maximus IX Code
                        • Intel Core i5-7600K 3.8GHz
                        • 16gb GSKILL TridentZ RGB DDR4-3200
                        • 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
                        • Windows 10 Pro x64
                        • GeForce GT1050
                          2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job )

                        Comment


                          #13
                          Re: Viewsonic VA912b messed up display

                          I agree.
                          The 400v is on the AC side, wouldn't cause your problem, and those rarely go out anyway short of a power surge.

                          Using all 25v for the 470uF is fine too.

                          I'd replace the 22uF just because I'm in there anyway and they are cheap.
                          [But that's just me.]

                          CapXon will have a 2 digit letter code that identifies the series.
                          'Series' is like a model name.
                          Need it to find the data sheet to find original ESR/Ripple for cross reference.

                          Diameter also helps. Units are mm.
                          Does no good to buy a fat one if only a skinny will fit.
                          Length only matters if you have height restrictions as installed.

                          .
                          Mann-Made Global Warming.
                          - We should be more concerned about the Intellectual Climate.

                          -
                          Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

                          - Dr Seuss
                          -
                          You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                          -

                          Comment


                            #14
                            Re: Viewsonic VA912b messed up display

                            Originally posted by PCBONEZ
                            I agree.
                            I'd replace the 22uF just because I'm in there anyway and they are cheap. [But that's just me.]
                            Yes, I agree. I forgot this little guy who has been causing trouble on 700G & 900G Gateways.
                            There are 10 kind of people in this world: those that understand binary, and those who don't.
                            • ASUS ROG Maximus IX Code
                            • Intel Core i5-7600K 3.8GHz
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                            • 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
                            • Windows 10 Pro x64
                            • GeForce GT1050
                              2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job )

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                              #15
                              Re: Viewsonic VA912b messed up display

                              The two digit code is KF.

                              Comment


                                #16
                                Re: Viewsonic VA912b messed up display

                                Tried to upload data sheet because CapXon's new site is an abortion but this site won't allow PDF's over 195.3k.
                                - Rather useless given that many PDF's are full color (and so larger) these days.

                                In KF series -> Ripple/ESR:
                                470uF 25V -> 1200/0.065
                                470uF 10V -> 580/0.250
                                22uF 50V -> 135/1.350
                                100uF 400V -> 950/0.520

                                Ripple is in mA at 105C and 100KHz -and- ESR is Ohms at 20C and 100KHz.
                                [Like they are supposed to be.]

                                If you go to Digikey, out of what they stock, you will need either Chemicon KZE or Panasonic FM to meet or beat those specs.

                                The 400v may be an exception. There are some series' that only come in higher volts and I dunno all of those off the top of my head. Probably don't need to replace that one anyway.

                                .
                                Mann-Made Global Warming.
                                - We should be more concerned about the Intellectual Climate.

                                -
                                Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

                                - Dr Seuss
                                -
                                You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                                -

                                Comment


                                  #17
                                  Re: Viewsonic VA912b messed up display

                                  I've just been through the same thing with my VX922. It would turn on (for a few seconds) then the green power light would start blinking long-on, short-off. After a few attempts, it was possible to get it to start and stay on, but turn it off and you get to play the whole game again.

                                  Getting it open is a pain -- four screws on the corners to remove, then force a metal spatula between the silver surround and the back of the case. There are about half a dozen clips holding it together -- unlock a corner first, then work your way around.

                                  Once you're in, there are some aluminium foil pads covering the shielding screws and connectors. But first... remove the jackposts for the DVI and VGA connectors.

                                  After you've got the jackposts out, remove the alu foil and the four screws holding the PCB shield to the display frame. Remove the following connectors:
                                  - Pink and blue cables left side top and bottom (4x) -- backlight drive. Squeeze the top of the connector, and pull out.
                                  - Black two-row mini-connector (1x), top side -- display data stream (LVDS?)
                                  - White mini-connector (1x), right side -- front panel connectors

                                  Once the connectors are out, lift off the shielding pack. The two PCBs (AC supply/backlight inverter and display driver) will come with it. Remove 7 screws and one plastic insulator plate, then lift out the PCBs.

                                  The PSU will probably be populated with Capxon capacitors. These are likely the ones causing the problem. As PCBONEZ et al mentioned, the 400V 100uF DC smoother rarely fails, so you can leave it if you like. Shotgun the rest of the capacitors, though. I decided that I didn't want my monitor breaking at another inopportune moment later on, so shotgunned the whole lot -- 8 capacitors in all

                                  If this doesn't fix the monitor, stare daggers at the Teapo capacitors on the driver board. Don't replace these unless you absolutely have to -- the PCB is multilayer (appears to be 4-layer, possibly more) was designed without thermal reliefs, so soldering the grounds on the capacitors is incredibly difficult. I replaced these as well, because I'm a glutton for punishment

                                  Reassembly is, as the saying goes, the reverse of disassembly

                                  After shotgun replacing every single electrolytic in the '922 with decent parts (Panasonic FM and FC series), it's working perfectly again. I could swear the video quality (even on VGA) is better than it has been for ages...

                                  FYI: This was done on a Viewsonic VX922, mfg date December/2006 (so it's a shade over 2 years old). I actually called Viewsonic, who basically told me that the "three year warranty" was "coincidentally" changed to a 2-year warranty last year, and my options were basically buy a new monitor or pay nearly £150 to have this one fixed, me paying shipping both ways, with no guarantee it'd be fixed or even that I'd get the same monitor back...

                                  Now I have no warranty (not that I had one to begin with), but I do have what I consider to be a "slightly souped up" VX922 that should hopefully last until the backlight tubes wear out

                                  I don't think I'll be buying another Viewsonic TFT... unless I have a severe lapse in judgement... or perhaps if Hell freezes over

                                  - Phil.

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                                    #18
                                    Re: Viewsonic VA912b messed up display

                                    Thank you everybody very much for all your input. I've been reading all the posts in the last few days and am going to take the time to recap the above mentioned caps this weekend. I'll post the results as soon as I have them. Thanks again!

                                    Comment


                                      #19
                                      Re: Viewsonic VA912b messed up display

                                      Hey guys I also have Viewsonic VA912B monitor, when turned on, I keeping hearing a click, some squealing through the built in speaker, and power just recycles on the monitor. I haven't opened it up yet, but does it sound like bad power supply? Where's a good place to order the power supply for these monitors if it is.

                                      Comment


                                        #20
                                        Re: Viewsonic VA912b messed up display

                                        Originally posted by marco916
                                        Hey guys I also have Viewsonic VA912B monitor, when turned on, I keeping hearing a click, some squealing through the built in speaker, and power just recycles on the monitor. I haven't opened it up yet, but does it sound like bad power supply? Where's a good place to order the power supply for these monitors if it is.
                                        Welcome to Badcaps.Net : cheers:
                                        It would be better if you try to fix yours first. Open the unit , take some pictures, and wait for an answer asking for specific information based on what your pictures show or don't show. It would be cheaper than hunting a power supply for the unit.
                                        There are 10 kind of people in this world: those that understand binary, and those who don't.
                                        • ASUS ROG Maximus IX Code
                                        • Intel Core i5-7600K 3.8GHz
                                        • 16gb GSKILL TridentZ RGB DDR4-3200
                                        • 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
                                        • Windows 10 Pro x64
                                        • GeForce GT1050
                                          2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job )

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