Re: [mythtv-users] Horizontal lines with NVidia TVout
On Sun, 2005-06-26 at 17:53 -0700, Fedor Pikus wrote: > On 6/26/05, Sérgio Gaspar <[EMAIL PROTECTED]> wrote: > > > > > > If this doesn't solve your problem then it's probably a ground loop caused > > by your cable provider. > > Bingo! Disconnect coax from wall - perfect picture. Connect coax - > lines start scrolling. I guess Tivo is not affected because it does > not have its own ground, it has a two-wire plug (so do TV and amp). > I'll have to figure out a way to tie the coax shield to the ground. I > hope something blows up at the cableco when I do and they fix their > floating ground :) > I made the exact same comment to myself when I tied mine to ground. I understand your feelings perfectly... Sergio ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Horizontal lines with NVidia TVout
On Sunday 26 June 2005 08:53 pm, Fedor Pikus wrote: > Bingo! Disconnect coax from wall - perfect picture. Connect coax - > lines start scrolling. I guess Tivo is not affected because it does > not have its own ground, it has a two-wire plug (so do TV and amp). > I'll have to figure out a way to tie the coax shield to the ground. I > hope something blows up at the cableco when I do and they fix their > floating ground :) If you've got a cable splitter or an amp somewhere on the line, you can probably just ground one of those. Bit easier. =) Isaac ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Horizontal lines with NVidia TVout
On 6/26/05, Sérgio Gaspar <[EMAIL PROTECTED]> wrote: > > Try pluging your myth box, TV set and AV system all to the same wall socket. PC is UPSed, plugging TV and the amp into the same UPS did not help. Tivo is also on the same UPS and there are no lines there. > > If this doesn't solve your problem then it's probably a ground loop caused > by your cable provider. Bingo! Disconnect coax from wall - perfect picture. Connect coax - lines start scrolling. I guess Tivo is not affected because it does not have its own ground, it has a two-wire plug (so do TV and amp). I'll have to figure out a way to tie the coax shield to the ground. I hope something blows up at the cableco when I do and they fix their floating ground :) Thanks! > > > Typically, a slow rolling band comes from a 60 Hz (or 50 depending on > > your localation in the world) AC source. Check for proper ground > > (ground loops will cause this). > > > > # Endaf > > > > Stuart Morgan wrote: > > > >>On Sun 26 June 2005 21:16, Fedor Pikus wrote: > >> > >> > >>>I've had my Myth box connected to a CRT and a small Toshiba TV (NVidia > >>>composite TV-out), and had excellent picture on both. Now I moved it > >>>to my AV system and connected it to a 32" Toshiba TV (CRT), I tried > >>>SVideo and Component out, and I always get the same problem: light and > >>>dark horizontal lines or bands slowly drifting up the screen, one or > >>>two lines at a time. Very visible when picture is dark, very annoying. > >>>It is not really specific to Myth: I see these lines on Fedora login > >>>screen, on my window manager screen after I log in, and in Myth > >>>everywhere. Interlacing options in Myth don't seem to help at all (and > >>>of course they would have no effect before Myth starts). The other > >>>problem I'm seeing is pretty strong pincussion distortion: left edge > >>>of the screen bends inwards. Increasing overscan helps with the > >>>distortion, to a degree, but the scrolling lines are unaffected. Any > >>>suggestions? > >>> > >>> > >> > >>Sound to me like interference - particularly magnetic. You haven't just > >> stuck > >>two huge speakers next to the TV have you? Or failing that is there > >> anything > >>with a strong EM field nearby (Microwave, electric motor or spacial > >> anomaly)? > >> > >> > > > > ___ > > mythtv-users mailing list > > mythtv-users@mythtv.org > > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users > > > > ___ > mythtv-users mailing list > mythtv-users@mythtv.org > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users > -- Fedor G Pikus ([EMAIL PROTECTED]) http://www.pikus.net http://wild-light.com ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Horizontal lines with NVidia TVout
Try pluging your myth box, TV set and AV system all to the same wall socket. If this doesn't solve your problem then it's probably a ground loop caused by your cable provider. I had the same problem a while ago and the solution was to get a 75ohm/75ohm balun to cut the loop, but as I was unable to get one of those and my cable provider (TVCabo in Portugal) refused to admit such a problem existed or was even possible, I solved the issue by connecting the RF cable shielding directly to the earth terminal in the wall socket. This way the current which flows because of different earth potentials goes directly to earth by the shortest route and does not interfere directly with demodulated signals inside your equipment, and you get a better picture and possibly eliminate a 50/60Hz buzzing sound you may hear coming from your AV subwoofer (have you noticed it?). As a side note, the horizontal stripes move across the screen because the power line frequency is not exactly the same as the video vertical frequency. As a second side note, I got one motherboard destroyed a few years ago most probably because of a ground loop. Loop currents can be sometimes large, but motherboard tracks and semiconductors are always weak. Sergio > Typically, a slow rolling band comes from a 60 Hz (or 50 depending on > your localation in the world) AC source. Check for proper ground > (ground loops will cause this). > > # Endaf > > Stuart Morgan wrote: > >>On Sun 26 June 2005 21:16, Fedor Pikus wrote: >> >> >>>I've had my Myth box connected to a CRT and a small Toshiba TV (NVidia >>>composite TV-out), and had excellent picture on both. Now I moved it >>>to my AV system and connected it to a 32" Toshiba TV (CRT), I tried >>>SVideo and Component out, and I always get the same problem: light and >>>dark horizontal lines or bands slowly drifting up the screen, one or >>>two lines at a time. Very visible when picture is dark, very annoying. >>>It is not really specific to Myth: I see these lines on Fedora login >>>screen, on my window manager screen after I log in, and in Myth >>>everywhere. Interlacing options in Myth don't seem to help at all (and >>>of course they would have no effect before Myth starts). The other >>>problem I'm seeing is pretty strong pincussion distortion: left edge >>>of the screen bends inwards. Increasing overscan helps with the >>>distortion, to a degree, but the scrolling lines are unaffected. Any >>>suggestions? >>> >>> >> >>Sound to me like interference - particularly magnetic. You haven't just >> stuck >>two huge speakers next to the TV have you? Or failing that is there >> anything >>with a strong EM field nearby (Microwave, electric motor or spacial >> anomaly)? >> >> > > ___ > mythtv-users mailing list > mythtv-users@mythtv.org > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users > ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Horizontal lines with NVidia TVout
Typically, a slow rolling band comes from a 60 Hz (or 50 depending on your localation in the world) AC source. Check for proper ground (ground loops will cause this). # Endaf Stuart Morgan wrote: On Sun 26 June 2005 21:16, Fedor Pikus wrote: I've had my Myth box connected to a CRT and a small Toshiba TV (NVidia composite TV-out), and had excellent picture on both. Now I moved it to my AV system and connected it to a 32" Toshiba TV (CRT), I tried SVideo and Component out, and I always get the same problem: light and dark horizontal lines or bands slowly drifting up the screen, one or two lines at a time. Very visible when picture is dark, very annoying. It is not really specific to Myth: I see these lines on Fedora login screen, on my window manager screen after I log in, and in Myth everywhere. Interlacing options in Myth don't seem to help at all (and of course they would have no effect before Myth starts). The other problem I'm seeing is pretty strong pincussion distortion: left edge of the screen bends inwards. Increasing overscan helps with the distortion, to a degree, but the scrolling lines are unaffected. Any suggestions? Sound to me like interference - particularly magnetic. You haven't just stuck two huge speakers next to the TV have you? Or failing that is there anything with a strong EM field nearby (Microwave, electric motor or spacial anomaly)? ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Horizontal lines with NVidia TVout
On Sun 26 June 2005 21:16, Fedor Pikus wrote: > I've had my Myth box connected to a CRT and a small Toshiba TV (NVidia > composite TV-out), and had excellent picture on both. Now I moved it > to my AV system and connected it to a 32" Toshiba TV (CRT), I tried > SVideo and Component out, and I always get the same problem: light and > dark horizontal lines or bands slowly drifting up the screen, one or > two lines at a time. Very visible when picture is dark, very annoying. > It is not really specific to Myth: I see these lines on Fedora login > screen, on my window manager screen after I log in, and in Myth > everywhere. Interlacing options in Myth don't seem to help at all (and > of course they would have no effect before Myth starts). The other > problem I'm seeing is pretty strong pincussion distortion: left edge > of the screen bends inwards. Increasing overscan helps with the > distortion, to a degree, but the scrolling lines are unaffected. Any > suggestions? Sound to me like interference - particularly magnetic. You haven't just stuck two huge speakers next to the TV have you? Or failing that is there anything with a strong EM field nearby (Microwave, electric motor or spacial anomaly)? -- Stuart Morgan ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
[mythtv-users] Horizontal lines with NVidia TVout
I've had my Myth box connected to a CRT and a small Toshiba TV (NVidia composite TV-out), and had excellent picture on both. Now I moved it to my AV system and connected it to a 32" Toshiba TV (CRT), I tried SVideo and Component out, and I always get the same problem: light and dark horizontal lines or bands slowly drifting up the screen, one or two lines at a time. Very visible when picture is dark, very annoying. It is not really specific to Myth: I see these lines on Fedora login screen, on my window manager screen after I log in, and in Myth everywhere. Interlacing options in Myth don't seem to help at all (and of course they would have no effect before Myth starts). The other problem I'm seeing is pretty strong pincussion distortion: left edge of the screen bends inwards. Increasing overscan helps with the distortion, to a degree, but the scrolling lines are unaffected. Any suggestions? -- Fedor G Pikus ([EMAIL PROTECTED]) http://www.pikus.net http://wild-light.com ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
