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Rolling black bar on output

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Quinn Costello
Rolling black bar on output
on Jul 15, 2008 at 8:52:56 pm

Hi-

I think I've tried everything now. I'm working with a 2007 Mac Pro Quad-Core Intel Xeon using FCP 6.3 and the Aja Kona LHe. I haven't always had this problem but whenever I capture using the component inputs (from my JVC BR-HD50u using DVCProHD 720p) I get a rolling black horizontal bar across the video. It's not always very noticeable but it's the worst on dark video and when I speed up clips. So here's what I've tried.

1. Replacing the card.

2. Switching out the breakout box.

3. Trying to import via firewire (looks fine but won't mix with everything I've already captured.)

4. Hooking my deck straight up to my tv monitor- also looks fine but I can't capture this way. Now I know it's not the deck or the monitor causing the issue.

5. Essentially something is happening on both the input and output of the component signal. For instance- when I preview a black clip of slug through the Kona card I get the rolling bar...so it doesn't have to be the video I've captured although I know from monitoring on my apple screen that it is indeed recording onto the video.

Thanks, as always, for all of your help.


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Jeremy Garchow
Re: Rolling black bar on output
on Jul 16, 2008 at 1:19:16 am

When you say rolling black bar, does it look like you messed with the vertical hold like on an older television or is it a 'hum bar' type of roll that's semi transparent in the footage?

If you are not playing any footage, do you see the bar move still or is it only when you play the footage?

Jeremy


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Ron Craig
Re: Rolling black bar on output
on Jul 16, 2008 at 4:42:13 pm

One possibility is a problem with electrical wiring, and Jeremy's question, above, is an important one in that regard. I'm unfortunately not at expert at wiring so all I can do is raise the possibility -- not give you a solution. Others here can help more on that.

Another thought is sync. Are you delivering a sync/blackburst signal to the Kona card, the deck and the monitor?


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Bob Zelin
Re: Rolling black bar on output
on Jul 17, 2008 at 1:22:06 am

everyone's guess is correct. You have an electrical hum problem. This is what you are going to do, and you are going to report back to us when you try this -

You are going to get a few cheap AC outlet strips (the kind you get at Home Depot, or Radio Shack). You are going to plug EVERYTHING IN YOUR SYSTEM - and I mean EVERYTHING into these cheap AC outlet strips. If you dont' have enough in one strip, you will DAISY CHAIN the strips together, so you are left with only ONE PLUG. You will plug this into your wall outlet, and have NOTHING ELSE PLUGGED IN TO ANY WALL OUTLET (other than lamps and telephones). This means that you will not have ANY mixers, powered speakers, plasma screen TV's, Cable TV boxes, etc. plugged in while you are doing these tests. The ONLY thing that is plugged into ANY wall outlet in your room is this one power cord that comes from the AC strip. (remember, if you have 3 strips with all the gear for your room, daisy chain them, so you only have one plug to plug into the wall).

Gee - I bet your hum problem went away - I bet you have no rolling bar thru your video now. You have an AC ground potential that NO ONE on this list can resolve for you. You need to hire a licensed electrician to come to your facility (or home), and run the low (the white wire), and the ground (the green wire) of each outlet in your room back to the SAME AC electrical panel. BUT ELECTRICIANS COST A LOT OF MONEY - CANT I JUST BUY A HUMBUCKER OR SOMETHING LIKE THAT -

NO NO NO NO NO NO NO.

Once you try this, if you still get the rolling bar, please write back.

Bob zelin




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Ron Craig
Re: Rolling black bar on output
on Jul 17, 2008 at 1:56:06 am

I love "hearing" Bob Zelin's voice on the board...



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Quinn Costello
Re: Rolling black bar on output
on Jul 18, 2008 at 4:02:26 am

Wow! Alright, we'll give that a try. Unfortunately I'm leaving on vacation but I promise to write back as soon as I've tried your test. Thanks for the response.



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