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Lines on LCD screen

Discussion in 'FPV (First Person View)' started by The Phantom, Aug 7, 2014.

  1. The Phantom

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    I have just set up a FPV system with the DJI AVL58 and some Boscam LCD screen with built-in receiver.
    There are a few lines on the screen traveling from the middle of the screen and upwards, when they come all the way up they disappear and it starts over again with lines appearing at the middle and going upwards. This is happening regardless of how near to the AVL58 the screen is. Even if they are an inch from each other it happens. I would have thought it was a reception issue if it were not for the fact that it happens regardless of the distance. I have the original antennas on both units, but i doubt that new antennas will make it better?

    Anybody that knows what this can be or has experienced a similar thing? Can it be that it is the channels that aren't exactly on the same frequency? But the picture is good aside from the mentioned problem.
    Or can it be something near the AVL58 on the drone that is disturbing the transmission? If so what can it be? The AVL58 is underneath the drone beside the FPV Hub kit board and the iosd Mini module.
     
  2. OI Photography

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    There could be a few causes for that depending on exactly how the lines look, but my guess is you also have an H3-3D with the new USB plug on it, and you're suffering from the same side effect as most others with the gimbal.

    If so, here's the best workaround I've seen so far: viewtopic.php?f=26&t=19936
     
  3. The Phantom

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    Yes i got the new H3-3D gimbal, it sounds like it could be that problem mentioned in the other thread. I have actually a couple of different problems with my gimbal so i would not be surprised if thats causing it. I will have to try it and see if it helps, but me myself would prefer to get the GoPro charged by the P2. Somebody also said in that same thread that the ribbon cable can get a stress fracture and that that is a common problem, is it really that common? and how to change the ribbon cable, doesn't it go into the gimbal and can't be loosened from that end?
     
  4. OI Photography

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    I was that somebody :) If you have the stress fracture I referred to, you wouldn't have any video from the camera at all, just iOSD data on a blank grey screen. And yes I would say that break is common, I think we've diagnosed several cases of the same in just the past week or so, and the design of the ribbon cable makes it easy (and almost inevitable) to happen.

    If you do end up needing to replace the cable for that reason at some point (which doesn't sound like the case yet), most major DJI dealers sell the replacement for $4-$5, and it plugs in to a port on the back of the gimbal that is identical to the one it slides in to on the little board with the USB port. You can delicately lift up the black rectangle sticker on the back of the gimbal and you'll see what I mean. You'll have to be careful, but it's not that hard.

    For the interference you're seeing now, I'd definitely at least try the fix in that other thread, just to confirm that's the true source of what you're seeing. You can then decide if it's worth using in the future or not. It looks to be a simple mod and easily and quickly reversible if you change your mind (or keep changing back and forth).
     
  5. The Phantom

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    Thanks for your help, i shall absolutely try it and see if thats the problem, at least it sound as it can be that thing. As you say its a pretty easy and fast thing to try, at least to know if thats the source for the problem. I appreciate your help.
     
  6. OI Photography

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    My pleasure! Whatever results you discover, please share in that other thread so we can add to the experience pool :)
     
  7. The Phantom

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    I will absolutely do that.
     
  8. Mike

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    Anybody have any advice for those of us with the old style connector on the H3-3d (the plug on the back of the GoPro)? I have the same video hum in mine. I know it's a power issue, but not sure how to solve it. Ferrite ring magnets? Any other thoughts?
     
  9. OI Photography

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    If you don't mind giving up the power feed to the camera, you can do the same mod I linked above, except on the ribbon cable yours has where the rear port connects to the gimbals electrical plumbing. It'll be a little more delicate of an operation in your case, but can certainly be done. This is what that connector looks like:

    [​IMG]

    The trick is to find which pins on there need to be masked for power, I don't know which are which on that one...I'm sure someone has mapped it and posted the pinouts.
     
  10. tferrari

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  11. Mike

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    Thanks, but that's for the USB plug. I have the older style. I'd really like to find a solution that doesn't involve cutting all power to the GoPro. I'll keep searching. If I figure it out, I'll make a new post.