Viewsonic vx2235 with bad caps

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • retiredcaps
    Badcaps Legend
    • Apr 2010
    • 9271

    #21
    Re: Viewsonic vx2235 with bad caps

    Originally posted by gregmcc
    When I switch the monitor on it flashes on and off for a fraction of a second and I can briefly see the correct grahpics on the screen. Then all goes dark.

    IC200 is a 20 pin chip:
    OZ964GN
    Okay, the flash makes a huge difference on where to look. The flash tells us that most of the circuitry is working.

    I can think 3 possible problems.

    1) One or more of your CCFLs are dying or bad.

    2) One of the inverter transformers is bad.

    3) Something else in the sense circuitry is causing the IC to shutdown the backlights.

    For #1 and #2, see

    https://www.badcaps.net/forum/showthread.php?t=10419

    If it comes down to #3, this will require more effort. Try #1 and #2 first and report your findings.
    --- 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

    • gregmcc
      Member
      • Aug 2007
      • 23

      #22
      Re: Viewsonic vx2235 with bad caps

      Thanks for the link. Only getting to this now.

      I've checked the transformers. I think they're the transformers. I'm getting completely different readings as mentioned in the link. I've attached pics of the transformers. They are the transformers I'm supposed to measure right?

      I get the following:


      Pin:
      8 9 10 11

      1 2 3 4 5 6 7

      Pin 1-8 1Mohm
      Pin 3-6 1Mohm

      All the other pins are open. I've desoldered the transformers and measured both. They both give the same readings.

      I also dont have a spare LCD so can't test the CCFLs.

      If it worth trying to source another inverter board and trying my luck? Not getting anywhere with this
      Attached Files

      Comment

      • retiredcaps
        Badcaps Legend
        • Apr 2010
        • 9271

        #23
        Re: Viewsonic vx2235 with bad caps

        Originally posted by gregmcc
        I've checked the transformers. I think they're the transformers. I'm getting completely different readings as mentioned in the link. I've attached pics of the transformers. They are the transformers I'm supposed to measure right?
        Yes, those are the transformers.

        I get the following:


        Pin:
        8 9 10 11

        1 2 3 4 5 6 7

        Pin 1-8 1Mohm
        Pin 3-6 1Mohm

        All the other pins are open. I've desoldered the transformers and measured both. They both give the same readings.

        I also dont have a spare LCD so can't test the CCFLs.

        If it worth trying to source another inverter board and trying my luck? Not getting anywhere with this
        Those readings are nothing like what I expected. I won't have access to my boards or a multimeter for a couple of days, but 1Mohm for the 2 readings is really high. I can understand one transformer being bad, but 2?

        I'm not as good as PlainBill as identifying which pins are the actual secondaries which is why the instructions are to measure all possible combinations.

        If you can list the part number of the transformer, you might be able to find it at http://www.lcdparts.net/T.aspx . If yes, that site documents which of the pins are secondaries and list the resistance reading you should expect. I would have expected somewhere between 900 ohms and 1600 ohms.
        --- 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

        • Mark369
          Senior Member
          • Jul 2009
          • 163

          #24
          Re: Viewsonic vx2235 with bad caps

          could some one tell me what the value of f200 is, I have same board and replaced caps and f200 is blowen monitor is working but i put jumper wire on for now.

          Comment

          • jetadm123
            Badcaps Legend
            • Feb 2010
            • 2169

            #25
            Re: Viewsonic vx2235 with bad caps

            Originally posted by Mark369
            could some one tell me what the value of f200 is, I have same board and replaced caps and f200 is blowen monitor is working but i put jumper wire on for now.
            Did the old fuse have a letter stamped on it? Different variations of your board specify a 3A fuse.

            Comment

            • Mark369
              Senior Member
              • Jul 2009
              • 163

              #26
              Re: Viewsonic vx2235 with bad caps

              sorry found it 3.3a glass

              Comment

              Related Topics

              Collapse

              • momaka
                Seasonic B12 BC-550 – barely 2 years old and with BAD CAPS already!
                by momaka
                I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.

                For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).

                https://www.badcaps.net/filedata/fetch?id=3591771


                https://www.badcaps.net/filedata/fetch?id=3591772

                It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:

                https://www.badcaps.net/filedata/fetch?id=359177...
                03-12-2025, 03:42 PM
              • momaka
                HannStar Hanns-G HC194d LCD monitor repair
                by momaka
                Normally, I never post repairs this quick after I do them, because… I am usually very slow. But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
                03-15-2023, 10:17 PM
              • eryjus
                Heathkit IO-4205 Power Supply Caps
                by eryjus
                Hello,

                First, I am a complete noob with high voltage stuff. I'm learning, but I need help by someone looking over my shoulder.

                I recently came into posession of a Heathkit IO-4205 5MHz Dual Trace Oscilloscope. The documentation is copyright 1978. I'm told it works.

                I opened it up to check the caps before I applied power, and found the following black caps and wanted to know what they were. They are on the power supply board. I was able to read the name and model and came up with, "Nytronics 162J-1, 0.1uF, 20% tolerance, 2000VDC."
                ...
                05-10-2023, 11:21 AM
              • Paxman_Swede
                Identifying caps on an old Zoom 9000
                by Paxman_Swede
                Hello!

                I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.

                The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.

                I have studied the board and...
                01-14-2025, 09:51 AM
              • captain150
                Help with switching power supply caps
                by captain150
                I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
                I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,...
                03-16-2025, 07:34 PM
              • Loading...
              • No more items.
              Working...