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barcoguy
Joined: 05 Feb 2008
Posts: 126
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 Link Posted: Thu Nov 20, 2008 8:04 pm Post subject: barco weirdness |
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Ok so I will try to explain this. I have a BG808 that does 2 things. I think its called streaking and ringing.
Streaking = a white area on a dark image causes horizontal bands to go off to the right side of the screen
ringing = It lighter colors such as the off white of this web page cause horizontal lines to roll on the image. It comes and goes and its not very obvious.
Any suggestions has anyone else ran into this problem?
thanks!
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Person99
Joined: 09 Mar 2006
Posts: 4901
Location: Flower Mound, TX
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| Link Posted: Thu Nov 20, 2008 10:15 pm Post subject: Re: barco weirdness |
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| barcoguy wrote: | Ok so I will try to explain this. I have a BG808 that does 2 things. I think its called streaking and ringing.
Streaking = a white area on a dark image causes horizontal bands to go off to the right side of the screen |
This is a common problem and I'm not sure there has ever been a fix for the neckboards yours has.
| barcoguy wrote: | | ringing = It lighter colors such as the off white of this web page cause horizontal lines to roll on the image. It comes and goes and its not very obvious. |
"ringing" is not rolling it more of an outlining. Is this what you are seeing?
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A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station....
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Fri Nov 21, 2008 2:47 am Post subject: |
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UGH
what if I get different neck boards what options do I have?
I will try and take a picture of it.
Its not a hum line or hum bar. Its sort of like noise.
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Z-Photo
Joined: 07 Mar 2006
Posts: 2753
Location: Huntsville - Alabama
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| Link Posted: Fri Nov 21, 2008 1:43 pm Post subject: |
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I have seen this when running 1080p through an extron and port 3.
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Person99
Joined: 09 Mar 2006
Posts: 4901
Location: Flower Mound, TX
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| Link Posted: Fri Nov 21, 2008 3:43 pm Post subject: |
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| barcoguy wrote: | UGH
what if I get different neck boards what options do I have?
I will try and take a picture of it.
Its not a hum line or hum bar. Its sort of like noise. |
Honestly, Ile is my go to guy on this stuff. He about 624 times smarter than me! 
Search for "streaking" and his posts here.
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Dave
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perisoft
Joined: 29 Aug 2007
Posts: 2920
Location: Ithaca, NY
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| Link Posted: Sat Nov 22, 2008 5:04 am Post subject: Re: barco weirdness |
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| barcoguy wrote: | Ok so I will try to explain this. I have a BG808 that does 2 things. I think its called streaking and ringing.
Streaking = a white area on a dark image causes horizontal bands to go off to the right side of the screen
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My g808s does this, but only with the contrast above 75 - you really have to crank it. I normally watch at 65... when does this kick in for you?
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Sat Nov 22, 2008 10:39 pm Post subject: |
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Let me check and I will see. Thanks guys!
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Link Posted: Sun Nov 23, 2008 7:27 pm Post subject: |
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I have seen streaking in all Barcos with 75 MHz rgb amps. (newer 801s, 808 and Data808s)
Removing abl have helped to every one. I have written procedure to remove abl, about 40 smd components need to be removed from every rgb amps.
My streaking test picture. Brightness need to be adjusted so that all four rectangles are shown.
http://www.curtpalme.com/forum/download.php?id=1342
Upper tube shot with stock 75 MHz rgb amps.
Lower tube shot with abl removed.
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Sun Nov 23, 2008 8:14 pm Post subject: |
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ABL jumper removed from rgb amp and it still streaks. Can you post a link to your procedure?
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Mon Nov 24, 2008 12:32 am Post subject: Re: barco weirdness |
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| perisoft wrote: | | barcoguy wrote: | Ok so I will try to explain this. I have a BG808 that does 2 things. I think its called streaking and ringing.
Streaking = a white area on a dark image causes horizontal bands to go off to the right side of the screen
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My g808s does this, but only with the contrast above 75 - you really have to crank it. I normally watch at 65... when does this kick in for you? |
mine does it @ 65
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Link Posted: Mon Nov 24, 2008 12:06 pm Post subject: |
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| barcoguy wrote: | | ABL jumper removed from rgb amp and it still streaks. Can you post a link to your procedure? |
Yes, removing abl jumpers doesn't make any difference. Video signal still goes through abl components and system is still active. I believe abl have been designed using crappy components (IC4 etc.) and it causes streaking problem and lower BW. I removed pretty much all abl related components.
Other option is to find 801 (non s) rgb amps 762173, it's same what 808 have (7621735) but without abl.
Can't say how well new 120MHz amp from BG808s work with old input and driver board. If it work there could still be some peaking mismatch (ringing), because those are designed to pair with other front end boards. 808s input and driver boards need also 808s controller board to work in 808...
I had to split pdf to get it posted.
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Mon Nov 24, 2008 11:53 pm Post subject: |
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| Ile wrote: |
Can't say how well new 120MHz amp from BG808s work with old input and driver board. If it work there could still be some peaking mismatch (ringing), because those are designed to pair with other front end boards. 808s input and driver boards need also 808s controller board to work in 808...
I had to split pdf to get it posted. |
Thanks that looks intense!
So if had 808s neckboards mod them to work with MEC tubes. Or 120mhz neckboards from a retro unit.... I tried the ones from a retro unit the streaking was gone! But it still had the (ringing)
You are suggesting changing out the following parts from an 808s
The driver R762720, input ? R762719 ? and switching controller or the weird board that has the eprom chip?
because the ringing is driving me nuts. The rest of the image looks grand!
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Z-Photo
Joined: 07 Mar 2006
Posts: 2753
Location: Huntsville - Alabama
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| Link Posted: Tue Nov 25, 2008 12:29 am Post subject: |
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The control only has the software -
Swap out the RGb boards
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Link Posted: Tue Nov 25, 2008 11:43 am Post subject: |
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Not sure if this all is going to help your noise problem, since also some 808s have this problem. Not sure yet what causes it. This is probably same problem what MP was having in some modded boards he sended to evaluation. It might have something to do with smps adding noise to some power rail.
| Z-Photo wrote: | The control only has the software -
Swap out the RGb boards |
808s have totally different menu inserting circuitry, so I remember that also whole controller board is needed to swap when input, driver and neck boards are taken from s.
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Z-Photo
Joined: 07 Mar 2006
Posts: 2753
Location: Huntsville - Alabama
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| Link Posted: Tue Nov 25, 2008 1:42 pm Post subject: |
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ile,
I have seen both - aPJ that need all of it swapped andalso a PJ that took just the board/amp swapout. I have also had on ehtt needed a few of the conv boards swapped ove rto remove an IC error.
I do not know of a hard and fast rule as to what works and what does not.
on a side not - I did go and swap out all of the big caps on the SMPS for FC/FM caps
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perisoft
Joined: 29 Aug 2007
Posts: 2920
Location: Ithaca, NY
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| Link Posted: Tue Nov 25, 2008 9:11 pm Post subject: |
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What I see on mine is more of a gradual horizontal bloom - you can see it move off to the right as you crank up the contrast, and it fades rather than being solid. So maybe it's something different.
I don't think I'd want to drive it any harder than 65 anyway (what do people run at?) so I'm not sure it matters for me. I'd be kind of upset if it did it at 65, though.
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Thu Nov 27, 2008 2:56 am Post subject: |
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| Ile wrote: | Not sure if this all is going to help your noise problem, since also some 808s have this problem. Not sure yet what causes it. This is probably same problem what MP was having in some modded boards he sended to evaluation. It might have something to do with smps adding noise to some power rail.
| Z-Photo wrote: | The control only has the software -
Swap out the RGb boards |
808s have totally different menu inserting circuitry, so I remember that also whole controller board is needed to swap when input, driver and neck boards are taken from s. |
I will try this it obviously did not work just putting in the two boards
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barcoguy
Joined: 05 Feb 2008
Posts: 126
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| Link Posted: Thu Nov 27, 2008 2:59 am Post subject: |
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I did switch out R7617481 the input control board modified by eisemann. Changing this board got ride of the ringing the picture is clean. But now it is a little darker and might have lost shadow detail. IE what the Eisemann mods do. So it looks like I need to send this board in for repair.
Unless I can get the same performance upgrade with the 808s parts??? Or is it better to have modified 808 parts?
Too many freaking boards!
Ok so increasing the gamma on the stock board leads to the ringing again. Does this provide a clue?
The eisemann board looks a MUCH better than the stock board!
Can we conclude that the "problem" is with one of these boards R7617481 and or R7621745
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Link Posted: Thu Nov 27, 2008 8:11 am Post subject: |
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Probably have nothing to do with gamma.
Hard to say is there something gone wrong with modified input board. Or is it catching noise much easier from defective smps or somewhere else because it have those crazy rf frequency transistors installed.
I'd send whole rgb board set + smps to Greg for checking.
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lydmann
Joined: 12 Aug 2006
Posts: 56
Location: Norway
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| Link Posted: Fri Dec 23, 2016 12:40 pm Post subject: |
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someone who have this pdf? cant find it here.
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