[mythtv-users] Refresh line being seen

[Brian Wood]

On Saturday 14 February 2009 11:02:41 MrVining wrote:
> On Feb 14, 2009, at 9:26 AM, Paulin wrote:
> > I'm having an old problem reappear after upgrading the NVidia
> > driver and then downgrading.  Can't seem to figure it out.
> >
> > 1. Upgraded to 180.22 NVidia driver.
> > 2. Eventually downgraded back to 180.16 driver.
> > 3. Put the .nvidia-settingrc file back from before the upgrade
> >
> > Now whenever watching a recorded program there is a thin line
> > scrolling down the screen every minute or so.
> >
> > Can anyone tell me what I should be looking at to correct this.  I
> > thought it was caused by the Nvidia settings but since they are
> > back to what they were before I updated/downgraded the driver I'm
> > not sure why it's happening.
> >
> > Any help would be appreciated.
> >
> > Thanks,
> > steve
>
> Is it possible that it is not driver related?  Has there been any
> physical changes made to the system.  I hear line slowly scrolling
> down the screen and I still jump right to grounding issue (retired
> cable guy).

With NTSC at least, a horizontal line scrolling slowly *up* the screen 
indicates 60 or 120 Hz. hum. The rate is the difference between the vertical 
rate being precisely 60Hz, and what it really is with NTSC color (in other 
words, if 3.579545 was in fact 3.600000, then the bar would be stationary).

A grounding issue would thus create a moving up bar, unless the scan rate of 
the video was far enough from 60Hz. to create a downward motion of the bar.

I tend to agree that the OP does not have a driver issue, more likely some 
sort of interference in the machine itself, the monitor, or the cabling, or 
some sort of common mode (ie: grounding) problem.

-- 
beww
beww at beww.org