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Gerbrand
Joined: 13 May 2008
Posts: 199
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| Posted: Sat Mar 14, 2009 4:13 pm Post subject: BG808: "Moire"effects at 50 Hz? |
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Hello all,
My BG808 has developed an issue, when displaying 48-50 Hz signals: at the top and bottom of the screen a kind of Moire pattern is visible (moving stripes). I can only see it if I display green and blue together, so I assume it is some kind of interaction between the green and blue scanlines.
If I increase the vertical resolution a bit, such that the scanlines disappear, the effect also goes away. BTW, I run at 864p where I can just see the scanlines in the center of the screen.
When the above happens, I can hear some noise coming out of the area around the G2 board, but I haven't been able to pinpoint it exactly.
My hypothesis so far is, that some power line ripple (I live in 50 Hz country) is entering the HV supplies, causing the scanlines to waver a bit.
Any ideas what could be happening here? Is anything dying on me?
Regards,
Gerbrand
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Tom.W
Joined: 09 Mar 2006
Posts: 6635
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Gerbrand
Joined: 13 May 2008
Posts: 199
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| Posted: Sat Mar 14, 2009 11:27 pm Post subject: |
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Tom,
I have been thinking about a groundloop problem also, so I have tried disconnecting and connecting cables, reversing the plug in order to change the polarity etc. So far the problem has persisted. I will try to post a screenshot sometime tomorrow, but basically the problem looks like "Moire": moving dark and bright stripes in bright areas (e.g. skies)
Cheers,
Gerbrand
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BG1209s (color filtered,new LUGs!), 13000h
Bat cave
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Gerbrand
Joined: 13 May 2008
Posts: 199
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| Posted: Sun Mar 15, 2009 5:31 pm Post subject: |
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Today I have continued looking for a groundloop issue. I have tried different wall sockets, different sources (scalar and HTPC), different ports (port 3 and port 5), but nothing seemed to have any effect.
In the end I increases the vertical resolution a bit. Although that helped, the whole image gets a bit softer.
Gerbrand
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BG1209s (color filtered,new LUGs!), 13000h
Bat cave
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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Gerbrand
Joined: 13 May 2008
Posts: 199
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| Posted: Sun Mar 15, 2009 6:42 pm Post subject: |
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I don't even own one... The video chain is HTPC (or scalar) - HDFury - Port 3, but i have also tried HTPC-Port 5 or Scalar-Port 5. All show the Moire effect.
Gerbrand
_________________
BG1209s (color filtered,new LUGs!), 13000h
Bat cave
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