Announcement

Collapse
No announcement yet.

128-G2 Video on Micro SD Inverted Colors?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 128-G2 Video on Micro SD Inverted Colors?

    I'm using the uOLED-128-G2 to play video clips from a micro sd card, and I'm getting "inverted colors" or a "washed out" look periodically. It will usually correct itself if I unplug the connector or shut off power, and then start it again. These displays are being powered by one of the 5v sources on a pinball machine, and I haven't had any issues on about 80 different devices, but I have had this same issue on about five devices. Is this an issue with my power harness? The issue is usually corrected after replacing the harness. I've had about 50 of these work correctly with a molex style 5-pin housing using trifurcon pins without any issues (twisted 2-wire hook up). The five I have had issues with have been using an IDC style connector, and the cables have not been twisted, they've been cinch tied together. I've noticed they aren't pinched into the slots very well on the IDC, as well. The crimping on the other end isn't very good on the plug end on some of these harnesses either. Would bad connectors and untwisted cables cause interference or this type of effect? Here is a youtube link of a short clip. The video is supposed to show a clip from the Star Trek movie, but the colors are inverted. Thanks

    https://www.youtube.com/watch?v=7n_p...ature=youtu.be
    Sparky

  • #2
    So the images are coming straight from the uSD, and not over serial (heaven forbid)?

    Is this 'hard on', or is it correct some/most of the time?

    What if you swap the uSD with another (good) unit's uSD card?

    Can you measure the 5v going into the display and see if it is stable?
    Mark

    Comment


    • #3
      The video is coming from the micro sd card. It doesn't happen all the time. It might start ok, and then it just happens. It won't go back to normal unless power is turned off, and then turned back on (or connector re-seated). If I swap the display with another known working display, it will happen again with the new display. If I move the suspect display to a different pinball machine, it won't happen anymore. If I move the micro sd card to another display it won't happen. If I move a known working micro sd card to the suspect game, it happens.

      It's specific to the pinball machine it's happening in. If I change the power harness I'm using, it usually solves it. I have two styles of harnesses. It has happened with five out of about 50 with one style of harness. It has happened with 0 out of about 40 of the other style. I know the easy answer is to stop using the suspect style of harness, but I wanted to make sure it's harness related.
      Sparky

      Comment


      • #4
        Well, from what you just said it is definitely harness related. Looks like the power is either getting serious noise injected into it, or it has too much resistance.
        Mark

        Comment


        • #5
          Would noise or resistance be created from a bad connector, bad crimp job, loose wire in the connector? Does twisted cable help eliminate noise?
          Sparky

          Comment


          • #6
            Could be any or all of the above
            Mark

            Comment


            • #7
              Thanks! I need to go back to making the harnesses myself
              Sparky

              Comment


              • #8
                I was able to get this problem to repeat 100% of the time by rubbing the metal nut I use for mounting against the card slot, so I switched to nylon lock nuts for mounting in case the metal nut was vibrating against the card slot. The issue has still occurred in a few more instances with nylon lock nuts, so it has to be something other than a metal nut vibrating against the card slot. These other instances are using harnesses with good connectors, but I'm wondering if interference or noise is getting picked up along the route of the wires. The harness is run alongside other wires that send 20v to 50v to coils and flashers.

                I have had no issues with about 150 devices now, which also run the same harness along other wires sending 20v and 50v, but issues with 10 specific machines keep popping up, even after switching displays, micro sd cards, changing to nylon lock nuts, and switching harnesses.

                I've purchased a couple hundred of these, and I'd like to have a definitive answer, so it doesn't keep happening.

                Do I need to insulate the two wires in my harness? I've been using 22awg on some and 24awg twisted on others. It's been ok for 140 others so far, but not these 10.
                Sparky

                Comment


                • #9
                  Can you show us a photo or two of the mounted display, from the rear?

                  Could these 10 specific machines have issues, um with
                  Mounting being stressed?
                  Extra vibration?
                  Extra 'noisy' bumpers (or arcing relays)?

                  How quickly does the issue occur?

                  What if you power the display with an external 5v supply?
                  Mark

                  Comment


                  • #10
                    Ok, I know it's been a few months, but here's an update on the continuing problem. Out of about 175 displays, this has occurred on 17 pinball machines. The problem stays with the specific pinball machine and does not move with the display. The display can be moved to other machines, including the same title, with no problems. Known working displays will have the problem when moved into the suspect game. The problem is not specific to a title or manufacturer, and all 175 games shake and vibrate the same or even more than the 17 where this is occurring.

                    I have also used uoled-160-g2's in about 100 machines with zero occurrences. However, the 160's are hot-glued into a model TV.

                    I have attached a pic of what the distorted video looks like. The video images are still visible, but the colors are crazy. If the video completes and loops back to the beginning, it will correct itself, until it happens again. Disconnecting/reconnecting power will also correct it, until it happens again.

                    I also attached a pic of the backside to show how the display is attached to a plastic bezel and mounting bracket. I am now using nylon lock nuts instead of the metal nuts, but it hasn't made a difference.

                    I thought the 5v supply from the pinball machine was regulated, but maybe it's not. On one particular game, I get multimeter readings that range from 5.16 to 5.26 during gameplay. I understand a multimeter is an average, and the actual readings might be higher.

                    Since I can force the occurrence by rubbing a metal screw on the back of the card slot, I was told that I was probably creating a negative charge that spikes just enough when the problem occurs. I was told that the 5v supply from the pinball machine's driver board might be spiking, as well. However, I have tried 5v wall wort adapters plugged into a service outlet, and the problem still occurs in the problem games.

                    It was suggested to try some different size capacitors at the +5v (#2 pin) and ground (my harness connects to the #1 pin and ground). A 1000uF cap was tested, and the problem occurred, along with some other "fuzzy" distortion. A 100uF cap was tested, and the "normal" problem still occurred.

                    It was suggested that my harness might be picking up interference, so snap choke cores were tested on three different games. The problem still occurred right away on two of the games. The third machine tested did not occur for several days, but the person testing had also not removed the 100uF cap, so results of whether the combination of the two are making a difference is unclear.
                    Attached Files
                    Sparky

                    Comment


                    • #11
                      Really sounds like some strong, possibly electromagnetic, interference.

                      Can you get a piece of mumetal and fashion a shield around the rear of the display.

                      I don't think that stuff is cheap, so you probably don't want to make it part of a standard installation, but anyway, I think you need to try it.
                      Mark

                      Comment

                      Working...
                      X